Assembly line fabrication and assembly of aircraft wings

ABSTRACT

Systems, methods, and apparatus are provided for assembling a wing. Methods include coupling a robot arm to a bracket on a rib held against a wing panel, and operating the coupled robot arm to install shims between the rib and wing panel. Some methods further include mounting (e.g. detachably) the bracket, such as by aligning it with indexing features at the rib. In some methods, the bracket enforces a contour to the rib. Systems include a carriage coupled to a rib, and a robot arm extending therefrom that is operable to perform work (e.g. inspection, installing shims and/or fasteners, etc.) at an interface between the rib and a wing panel. Apparatus includes a robot arm dimensioned for placement at an interface between a rib and a wing panel, with the robot arm including an end effector to perform work upon the interface (e.g. inspection, installing shims and/or fasteners, etc.).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 63/115,056, filed Nov. 18, 2020, and entitled“Assembly Line Fabrication and Assembly of Aircraft Wings;” which isincorporated herein by reference in its entirety.

FIELD

The disclosure relates to the field of aircraft, and in particular, tofabrication and assembly of aircraft wings.

BACKGROUND

An airframe defines the mechanical structure of an aircraft. Airframesare made of multiple components that provide desired structuralproperties. For example, a portion of an airframe for a wing of anaircraft may include components that are mechanically coupled together(e.g., via co-bonding, co-curing, or fasteners) in accordance withdesign parameters. In particular, a wing assembly generally includesupper and lower wing panels, each of which include a wing skinstabilized by a series of stringers, that together sandwich a supportstructure consisting of forward and rear spars that extend along thespan of the wing panels, and that are connected together by a series ofparallel ribs that each extend chordwise across the wing panels. Aspresently practiced, components of an airframe are fabricated andassembled in predefined cells on a factory floor. For example,components may be laid-up, cured, or otherwise fabricated at one cell,and then may be transported in their entirety to a new cell where workis performed.

While the fabrication processes discussed above are reliable, theyencounter delays when work at a specific portion of a component iscompleted more slowly than expected. For example, if a particularportion of a wing takes longer than expected to be laid-up or fastenedtogether, then the entire wing assembly remains at the cell until all ofthe work that has been delayed is completed. Furthermore, after acomponent has been moved, a great deal of time is spent cataloging theconfiguration of the component. This time is not value-added time.Furthermore, frequent moves between cells add a substantial amount oftime that is not value-added. That is, each movement of a componentbetween cells (and hence, each cell used in the fabrication process)requires setup time, and this setup time should be minimized to enhanceefficiency. Current designs utilize automated optical inspectiontechniques and/or probes to inspect position of parts along six degreesof freedom across their dimensions, but these are particularlytime-consuming and expensive processes.

Therefore, it would be desirable to have a method and apparatus thattake into account at least some of the issues discussed above, as wellas other possible issues.

SUMMARY

Embodiments described herein provide for enhanced systems and techniquesthat facilitate fabrication and assembly of aircraft wings via anassembly line. According to these embodiments, large components such aswing panels are transported in pulses or moved continuously. Discretework stations disposed along the assembly line perform various worktasks on the component (e.g., during pauses between pulses or while thecomponent is moved continuously). As discussed in greater detail below,the embodiments herein focus on assembling a wing assembly by followingthe progress of a wing panel, to which other components (for example,ribs, and spars, and then another wing panel) are gradually installed,through an assembly line. In some embodiments, indexing features, forindexing the component (e.g., a wing panel) to one or more of the workstations, are formed into the component. In embodiments in which thecomponent is a wing panel, indexing features are formed into amanufacturing excess region of the wing panel that will eventually betrimmed off, as part of the forming of the wing panel. The wing panelmay be indexed to a work station by means of these indexing features. Insome embodiments, work stations are disposed in close enough proximityto each other such that a wing panel, due to its size, may encountermultiple work stations simultaneously. For example, an assembly line mayinclude a sequence of stations arranged in a process direction so that aforward portion of the wing panel first encounters an inspection station(such as a non-destructive inspection, or NDI, station), then a cut-outstation, and then a rib install station, as it is moved in the processdirection. These stations may be disposed closely enough to each otherso that when, for example, a forward portion encounters the rib installstation, a middle portion of the wing panel encounters the cut-outstation, and a rearward portion encounters the NDI station, such thattwo or more of the stations, or all three, may perform work tasks on theportion of the same wing panel that is within the purview of therespective station, such as at the same time or overlapping in time.This assembly technique provides a technical benefit by integratingtransportation processes into assembly processes, and by reducing theamount of work to be performed on a large component each time thecomponent is moved.

Some embodiments are methods for inspecting a wing panel, in which themethods include: advancing the wing panel in a process direction througha Non-Destructive Inspection (NDI) station having one or more inspectionheads, and inspecting a portion of the wing panel with one or moreinspection heads at the NDI station. Some methods further includesuspending the wing panel beneath a strongback, for example prior toadvancing the wing panel through the NDI station, such that the wingpanel remains suspended beneath the strongback during advancementthrough the NDI station and inspection at the NDI station. In some ofsuch methods, suspending the wing panel includes affixing vacuumcouplers of the strongback to a surface of the wing panel. Some methodsfurther include enforcing a predetermined contour to the wing panel,such as during advancement and/or NDI inspection of the wing panel. Somemethods further include indexing the wing panel to the NDI station.

Some embodiments are methods for inspecting a wing panel, in which themethods include: receiving a wing panel at a Non-Destructive Inspection(NDI) station having one or more inspection heads, and inspecting aportion of the wing panel with one or more inspection heads at the NDIstation during movement of the wing panel through the NDI station. Insome methods, inspecting is performed during pulsed or continuousmovement of the wing panel through the NDI station.

Some embodiments are non-transitory computer readable media embodyinginstructions which, when executed by a processor, are operable forperforming the methods briefly mentioned above.

Some embodiments are systems for inspecting a wing panel, in which thesystems include: a track; a strongback configured to suspend a wingpanel beneath it, and to advance along the track in a process direction;and a Non-Destructive Imaging (NDI) station disposed at the track andthat is configured to inspect the wing panel while the wing panel issuspended beneath the strongback. In some systems, the strongback isconfigured to enforce a predetermined contour onto the wing panel bymeans of adjustable-length pogos that include vacuum couplers. Somesystems further include a controller configured to perform variousactions, such as selectively retracting one or more vacuum couplers toallow NDI inspection of the wing panel, detecting out-of-toleranceconditions at the wing panel based on input from the NDI station,reporting out-of-tolerance conditions for rework, controlling operationof inspection heads of the NDI station, controlling advancement of thewing panel in the process direction, and relating input from the NDIstation relating to locations on the wing panel. In some systems, theNDI station is configured to index with the wing panel and/or thestrongback suspending the wing panel.

Other illustrative embodiments (e.g., methods, computer-readable media,systems, and so forth, relating to the foregoing embodiments) may bedescribed below. The features, functions, and advantages that have beendiscussed can be achieved independently in various embodiments or may becombined in yet other embodiments further details of which can be seenwith reference to the following description and drawings.

DESCRIPTION OF THE DRAWINGS

Some embodiments of the present disclosure are now described, by way ofexample only, and with reference to the accompanying drawings. The samereference number represents the same element or the same type of elementon all drawings.

FIG. 1 is a block diagram of a layup system that applies indexingfeatures to a manufacturing excess of a preform that will be hardenedinto a composite part in an illustrative embodiment.

FIG. 2A illustrates a layup mandrel awaiting layup in an illustrativeembodiment.

FIG. 2B illustrates a layup mandrel covered by a composite part in anillustrative embodiment.

FIG. 3 is a flowchart illustrating a method for applying indexingfeatures to a manufacturing excess of a preform that will be hardenedinto a composite part in an illustrative embodiment.

FIG. 4 depicts takt timing for feeder lines for a composite part in anillustrative embodiment.

FIGS. 5A-5F are diagrams of an assembly line for a wing in anillustrative embodiment.

FIG. 5G is a diagram of an alternative configuration of an assembly linefor a wing in an illustrative embodiment.

FIG. 6 is a flowchart illustrating a method of enforcing a contour ontoa wing panel in an illustrative embodiment.

FIGS. 7 and 8 are flowcharts illustrating methods of non-destructiveinspection of a wing panel in an illustrative embodiment.

FIG. 9 is a flowchart illustrating a method of installing ribs and sparsto a wing panel in an illustrative embodiment.

FIG. 10 is a flowchart illustrating a further method of enforcing acontour onto a wing panel in an illustrative embodiment.

FIGS. 11A-11D illustrate installation of a rib at an upper wing panel inan illustrative embodiment.

FIG. 12 is a flowchart illustrating a method of affixing a rib to anupper wing panel in an illustrative embodiment.

FIGS. 13-15 are flowcharts illustrating methods of installing ribs andspars to an upper wing panel in an illustrative embodiment.

FIGS. 16A-16C are diagrams illustrating automated installation of shimsbetween ribs and wing panels in illustrative embodiments.

FIGS. 17A-17C illustrate further views of a robot arm performingautomated inspection and shim installation between ribs and wing panelsin illustrative embodiments.

FIG. 18 is a flowchart illustrating a method of shim installation usinga robot arm in an illustrative embodiment.

FIG. 19 is a perspective view of an aircraft that includes a fullyassembled wing in an illustrative embodiment.

FIG. 20 is a block diagram of various components and systems discussedherein in an illustrative embodiment.

FIG. 21 broadly illustrates control components of a production systemthat performs ultrasonic inspection in an illustrative embodiment.

FIG. 22 depicts an assembly line in an illustrative embodiment.

FIG. 23 is a flow diagram of aircraft production and service methodologyin an illustrative embodiment.

FIG. 24 is a block diagram of an aircraft in an illustrative embodiment.

DESCRIPTION

The figures and the following description provide specific illustrativeembodiments of the disclosure. It will thus be appreciated that thoseskilled in the art will be able to devise various arrangements that,although not explicitly described or shown herein, embody the principlesof the disclosure and are included within the scope of the disclosure.Furthermore, any examples described herein are intended to aid inunderstanding the principles of the disclosure, and are to be construedas being without limitation to such specifically recited examples andconditions. As a result, the disclosure is not limited to the specificembodiments or examples described below, but by the claims and theirequivalents.

For convenience, the description is presented as a sequence ofoperations that may occur in the production of a wing for an aircraft,as it is assembled on an assembly line from constituent parts. Inparticular, the description begins with the formation of a wing panelfrom a preform, and proceeds through various operations performed on thewing panel, including the addition of structural components such as ribsand spars to the wing panel (which may be an upper wing panel), andjoining another wing panel (such as a lower wing panel) to form a wingassembly. The term “wing assembly” is used herein generally to refer toa wing panel to which one or more major structural components, e.g. ribsand spars, has been affixed or installed, and may thus include acomplete wing. However, as the description refers mainly to theformation of a wing panel and the addition of major structuralcomponents thereto, and not necessarily to the inclusion of cabling andmechanical and electrical systems that are typically also incorporatedinto a completed wing. Not all operations, processes, steps, and otheractions described herein necessarily take place in all of theembodiments (e.g., embodiments of wing assemblies, embodiments ofstructural components thereof, embodiments of methods relating to theassembly thereof, etc.) described herein, or in other embodiments thatare consistent with this disclosure. Further, the operations described,or certain actions included therein, may take place in a different orderthan as discussed, may take place at the same time or overlapping intime with other actions, may represent alternative operations fordifferent wing panels (such as an upper wing panel as opposed to a lowerwing panel, etc.), and so forth.

The wings and wing assemblies described herein may comprise metal partsand/or composite parts. Composite parts, such as carbon fiber reinforcedpolymer (CFRP) parts, are initially laid-up in multiple layers thattogether are referred to as a preform. Individual fibers within eachlayer of the preform are aligned parallel with each other, but differentlayers exhibit different fiber orientations in order to increase thestrength of the resulting composite part along different dimensions. Thepreform includes a viscous resin that solidifies in order to harden thepreform into a composite part (e.g., for use in an aircraft). Carbonfiber that has been impregnated with an uncured thermoset resin or athermoplastic resin is referred to as “prepreg.” Other types of carbonfiber include “dry fiber” which has not been impregnated with thermosetresin but may include a tackifier or binder. Dry fiber is infused withresin prior to curing. For thermoset resins, the hardening is a one-wayprocess referred to as curing, while for thermoplastic resins, the resinreaches a viscous form if it is re-heated.

FIG. 1 is a schematic diagram of an illustrative layup system 100 thatapplies indexing features to a manufacturing excess of a preform thatwill be hardened into a composite part in an illustrative embodiment. Inprior systems, manufacturing excess for a composite part—that is,material that is beyond the intended final dimensions or boundaries(e.g., the final perimeter) of the composite part—is trimmed immediatelyafter demolding. For example, this may include placing a wing panel intoa dedicated cell, scanning the wing panel to characterize it, and thentrimming the wing panel (e.g., with a cutter) along the perimeter of thepart until final perimeter dimensions are accomplished. Similarprocesses are applied when trimming manufacturing excess for a fuselage.As will be described in greater detail herein, layup system 100 isunique in that it utilizes material that is traditionally immediatelytrimmed from a composite part after demolding. In particular, variousindexing features are formed into the manufacturing excess of thepreform, which can then be used to index (e.g. position, orient,identify, etc.) the hardened composite part for further operations, suchas at one or more stations in an assembly line or other manufacturingprocess. Layup system 100 comprises any system, device, or componentoperable to apply indexing features to a preform which will be hardenedinto a composite part. In this embodiment, layup system 100 includes alayup mandrel 110 (e.g., a rigid metal mandrel) that defines a contour112 (e.g., a curved, flat, or otherwise shaped contour) for a preformthat will be hardened into a composite part, such as a wing panel. Apreform 200 is shown to be disposed on the layup mandrel.

As can also be seen with reference to FIGS. 2A and 2B, which show anisometric view of a simplified version of layup mandrel 110, the mandrelhas surface features 114, such as indents, protrusions, ridges, grooves,notches, through-holes, blind holes, dams, etc. Like contour 112, whichimparts a corresponding contour to the preform, surface features 114 arecapable of being used to directly place corresponding indexing features,shown at 210, onto the preform. Others accommodate trimming ofmanufacturing excess at the layup mandrel 110, or drilling of acomposite part hardened at the layup mandrel 110. In other words, thesurface features 114 alter the shape of the preform 200 on a localizedbasis to place the indexing features 210 into the preform and/orhardened composite part, with the various types of surface features 114offering different ways of forming the indexing features into thecomposite part. One way is in laying up the preform over a surfacefeature (e.g., a protrusion, which forms a corresponding indent in thepreform that becomes part of the composite part after hardening);another way is by machining (e.g., by drilling) an indexing feature(e.g., a through-hole) into the composite part post-hardening. Forexample, in FIG. 1, surface features 114 are shown to include recesses118 that are filled with potting compound and finished to a surfacecontour to complement the contour 112, so that indexing features such asthrough-holes may be drilled into the composite part hardened from thepreform 200 prior to de-molding the part from the mandrel 110, withovershoot during the drilling operation removing some of the pottingcompound rather than damaging the surface of the layup mandrel. Thesurface features 114 are used to shape, or enforce, indexing featuresonto (and/or into) a preform 200 laid-up onto the layup mandrel 110.

Overshoot during machining, such as drilling or trimming, at the layupmandrel 110 after hardening necessitates rework of the potted surface(s)prior to the next use of the layup mandrel 110. The preform 200 islaid-up onto the layup mandrel 110 over the contour 112 and surfacefeatures 114.

As shown in FIG. 1 and as is also visible in FIG. 2A, which shows layupmandrel 110 awaiting a layup, the layup mandrel includes a layup region120 for preform 200, which includes contour 112, and which is surroundedby a manufacturing excess region 122, within which are disposed surfacefeatures 114. Correspondingly, preform 200 is shown in FIG. 1 to extendpast a final trim boundary or final perimeter 202 for the resultingcomposite part. The region of the preform that extends beyond the finalperimeter 202 is the manufacturing excess, indicated at 204, which isdefined by a manufacturing excess edge 206. Accordingly, surfacefeatures 114 are positioned to complementarily form indexing features210 in preform 200. More particularly, the surface features 114 that aredisposed in the manufacturing excess region 122 form indexing features210 in the manufacturing excess 204 of preform 200 before hardeningwhich, as noted above, may be utilized for indexing after the preform200 has hardened into composite part 250. Although the curve of contour112, which is shown as a shallow, concave surface, is shown to extend onlayup mandrel 110 beyond the final perimeter 202 of the resultingcomposite part, this is not required to all embodiments, as the contour112 is only required for the portion of the resulting composite partthat is within the final perimeter 202. Also, while a concave layupmandrel 110 is illustrated, layup mandrels of any suitable shape may beutilized. For example, convex layup mandrels, and layup mandrels thatdefine complex curvatures, are also possible. Also, while an outer moldline layup mandrel 110 is illustrated, inner mold line layup mandrelsmay be utilized in another embodiment.

While FIG. 2A shows layup mandrel 110 awaiting a layup, FIG. 2B shows acomposite part, indicated at 250, which has been hardened from a preform200, awaiting demolding from layup mandrel 110. Indexing features 210 ofpreform 200 have become indexing features 210 of composite part 250.

In some embodiments, the surface features 114 are separated fromneighboring surface features by a predefined distance (e.g., severalinches, several feet, etc.), such as to create evenly spaced indexingfeatures 210 at/on/in the preform 200 and resulting composite part 250.In another embodiment, the surface features 114 are unevenly spaced fromeach other. The positions and/or predefined distance(s) between indexingfeatures may depend, in part, on factors such as the arrangement of workstations on an assembly line.

Positions of the surface features 114 in the layup mandrel 110 areprecisely toleranced (e.g., to a thousandth of an inch), and hence thepositions of corresponding indexing features 210 at the preform 200 arealso consequently known to a precise tolerance, even after the preform200 has been hardened into composite part 250 and demolded from layupmandrel 110. Thereafter, the indexing features 210 may be utilized bystations in an assembly line in order to orient and position theresulting composite part in a desired manner so that work may beperformed upon the composite part. Furthermore, because the layupmandrel 110 is re-usable, there is no need for a separate process ofapplying indexing features to preforms. Performing this process at alayup mandrel that is within tolerance results in indexing features thatare also within tolerance. Recesses 118, also referred to as pottingareas, are filled with a potting compound and placed to accommodatemachining overshoot from a machining operation such as drillingoperation to install indexing features (e.g. through-holes) afterhardening into composite part 250 has been completed, as noted above,and refilled and/or resurfaced as necessary after machining andde-molding in order to prepare for the next preform.

Some embodiments include installing readable identifying means (showngenerally at 126 in FIG. 1) in the preform, such as a Radio FrequencyIdentifier (RFID) chip. In such embodiments, one or more RFID chips arecoupled, attached, or embedded into the manufacturing excess 204 of apreform 200. Readable identifying means such as an RFID chip canfacilitate the indexing process by reporting information thatcharacterizes aspects of the resulting composite part to which it iscoupled. For example, an RFID chip can provide instructions to a workstation regarding the portion of the structure within the purview of theparticular work station. One or multiple RFID chips can provideinstructions to one work station or multiple work stations, and there isno need for a one to one relationship of one RFID chip to one workstation. In another example, the RFID chips report a type ofstructure/wing, including right or left, or upper or lower, or evenmodel number, to the work station.

Further, although not shown in the drawings, one or more other readableidentifying means 126 may be provided to preform 200, or to thecomposite part 250 formed therefrom, as part of the forming process, inaddition to or instead of an RFID chip. For example, a bar code or otherindicia, which may be scanned or read by a suitable reader by one ormore work stations in an assembly line, may be inscribed or applied tothe preform or resulting composite part, prior to de-molding. For thesake of this disclosure, all references herein to a particular type ofreadable identifying means 126 (such as an RFID chip, or a bar code)(and depictions thereof, in the drawings) are intended to broadlyencompass any such readable identifying means.

The layup system shown in FIG. 1 further includes a cutter 130 having ablade 132 (e.g., a reciprocating or circular blade) and an actuator 134that drives the blade 132 to cut portions of a composite part that areproximate to guides 116, which are shown in the form of adjoininggrooves that encompass the manufacturing excess region 122, in the layupmandrel 110. That is, the guide 116 seats the cutter 130 and/or definesa path for cutter 130. Moreover, as shown in FIG. 1, the guide 116 maybe filled with potting compound to accommodate a blade of the cutter(and refilled after use, similar to recessed areas 118). As shown inFIG. 2B, for example, in which the grooves that collectively form guide116 are shown for clarity as a rectangular perimeter, composite part 250is shown to include a portion 252 that is within layup region 120, aswell as a portion 254 in the manufacturing excess region 122 that isconformed to surface features 114. A flash edge 256 of surplus materialis shown in FIG. 2B to extend beyond the manufacturing excess region122. The cutting operation, which is performed prior to demolding of thecomposite part 250 from the layup mandrel 110, removes flash edge 256 todefine a manufacturing excess edge 206, and leaves a sufficient amountof manufacturing excess 204 to include indexing features 210 for use bystations in an assembly line. The rough cut provides a consistent edge,i.e. manufacturing excess edge 206, to the part during the manufacturingprocess, prior to trimming the edge to a final perimeter, i.e. finalperimeter 202. This is desirable in contrast to working upon a partwithout a fixed consistent perimeter with respect to a manufacturingexcess. Operations of the cutter 130 are managed by controller 140.Controller 140 may be implemented, for example, as custom circuitry, asa hardware processor executing programmed instructions, or somecombination thereof.

Illustrative details of the operation of layup system 100 will bediscussed with regard to FIG. 3 and method 300 shown therein. Assume,for this embodiment, that layup mandrel 110 has been cleaned andreturned to the start of an assembly line after a composite part hasbeen demolded from the layup mandrel 110. Thus, layup mandrel 110 awaitslayup of a preform, such as preform 200, for a next composite part 250.

FIG. 3 is a flowchart illustrating a method 300 for applying indexingfeatures to a manufacturing excess 204 of a preform 200 that will behardened into composite part 250 in an illustrative embodiment. Thesteps of method 300 are described with reference to components of layupsystem 100 shown in FIGS. 1, 2A, and 2B, but those skilled in the artwill appreciate that method 300 may be performed in other systems. As isthe case with all of the methods illustrated and described in thisdisclosure, the steps shown in the flowchart described herein areneither all inclusive nor exclusive. Furthermore, the flowcharts herein(such as in FIG. 3) illustrate only a specific embodiment of aparticular method (such as method 300), it will be understood that otherembodiments of methods consistent with and encompassed by thisdisclosure include a fewer or greater number of steps than as shown,include steps performed in a different order than as shown in, and/orcontain other (e.g., additional, fewer, and/or alternative) actions thanas depicted. Further, as will become clear from the disclosure, as thevarious methods shown and discussed herein relate to several differentoperations and sequences that may be performed as a wing panel is formedand assembled into a wing assembly, methods in accordance with thisdisclosure may combine or otherwise include various steps and operationsof two or more of various illustrated methods. Also, although referencenumbers for components described above are used in the description ofthis method 300, it will be understood that the method (as well as othermethods described herein) is applicable to components that may havedifferent configurations than as illustrated and described above.

Focusing on method 300, in step 302, a preform 200 is laid-up onto thelayup mandrel 110, such as onto a layup region 120, as well as onto aportion of the layup mandrel 110 that is located beyond final trimboundaries (i.e., the final perimeter 202) of the composite part 250,such as a manufacturing excess region 122. Manufacturing excess region122 of the layup mandrel 110 includes surface features 114 configured tocomplementarily form indexing features 210 in the preform 200. The layupmandrel 110, in at least the layup region, defines a contour 112 for acomposite part, and the preform 200 includes a manufacturing excess 204that extends beyond the final perimeter for the composite part. Layupmay be performed as the layup mandrel 110 itself is pulsed or movedcontinuously through an assembly line, and may include the synchronizedoperation of multiple lamination machines at once (e.g., duringcontinuous motion of the layup mandrel, during pauses between movementsof the layup mandrel, etc.). During layup, multiple plies ofunidirectional fiber reinforced material are applied sequentially tobuild the preform 200 at a desired size and strength. The layup processextends the preform 200 beyond final trim (e.g. assembly-size)boundaries (e.g. beyond a final perimeter 202), which means that aportion of the preform 200 extends over surface features 114. In thisembodiment, the preform 200 is a preform for a wing panel 550 withmultiple layers/plies.

In step 304, the preform 200 is conformed to surface features 114 at thelayup mandrel 110 that are located beyond the final trim boundaries ofthe composite part 250 and that complementarily form/enforce featuresinto the preform 200 that will be hardened into indexing features 210.In one embodiment, this comprises consolidating the preform 200 byvacuum bagging the preform and applying consolidation pressure. Infurther embodiments, tows of fiber-reinforced material applied duringlayup in step 302 are compressed by a roller or other device to conformthe preform 200 to the surface features 114.

In the illustrative method, steps 302 and 304 are usually performed in aclean room environment, to minimize the possibility of foreign objectdebris and other contaminants from contacting the preform 200, such asduring layup. The layup mandrel 110 is then moved to an autoclave, whichhardens the preform 200 into a composite part 250 via the application ofheat and/or pressure. In step 306, the preform 200 is hardened into acomposite part 250 that includes indexing features 210 complementarilyformed therein, in that the indexing features 210 are complementary tothe surface features 114, and are disposed at the surface features 114.During hardening, the preform 200 may be heated to a curing temperaturefor a thermoset resin within the preform 200, or the preform 200 may beheated to a melting temperature of a thermoplastic resin and then cooleduntil the thermoplastic resin solidifies. This results in the resultingcomposite part 250 having indexing features 210 disposed at the surfacefeatures 114 on the layup mandrel 110.

In further embodiments, additional indexing features 210 are added bymilling or drilling the manufacturing excess, such as by installingholes, notches, channels, and/or grooves that remove material from themanufacturing excess. In still further embodiments, additional indexingfeatures 210 such as pins, clips, rings, etc. are utilized and/orinstalled.

Some embodiments include installing readable identifying means 126 (suchas an RFID chip, a bar code, and so forth) to the manufacturing excess204, either of the preform 200 or of the composite part 250. Phrasedanother way, RFID chip and/or other readable identifying means 126 areplaced in manufacturing excess 204 either prior or subsequent tohardening the preform into the composite part 250.

In step 308, material is removed (e.g., cut or otherwise separated) fromthe composite part 250 while retaining a manufacturing excess 204 thatincludes the indexing features 210. The cutting operation of step 308creates a consistent perimeter/border of manufacturing excess 122. Inone embodiment, this comprises operating a cutter 130 along guides 116in order to cut away a resin flash (or flash edge 256) or other borderof the composite part 250, resulting in a manufacturing excess edge 206.In one embodiment, trimming off flash edge 256 of the composite part is250 performed prior to demolding the resulting composite part 250 fromthe layup mandrel 110. The composite part 250 retains manufacturingexcess 204 having indexing features 210 that will be used for indexingthe composite part as it is worked upon by work stations in an assemblyline. The composite part 250 may also include indexing features 210 inareas that will be trimmed off to accommodate, for example, wing accessdoors or other portions of a wing panel, and/or manufacturing excessbeyond a wing panel final perimeter. A final perimeter 202 can then beachieved by trimming off the remaining manufacturing excess later in theprocess. That is, one or more of the indexing features may be subject toremoval to accommodate the addition of one or more components duringassembly. For example, work stations can be designed to trim outmanufacturing excess or portions thereof, install components such asribs or spars, join components such as wing panels together, etc. Infurther embodiments, additional indexing features 210, such as holes,notches, channels, grooves, and so forth, are installed into/formed atthe composite part 250 via drilling, milling, or other operations. In afurther embodiment, removing material from the composite part 250comprises installing such additional indexing features 210.

In step 310, after removing material, such as separating flash edge 256and/or placing indexing one or more indexing features 210, from thecomposite part 250, the composite part is demolded from the layupmandrel 110. The composite part 250 then proceeds (not shown) to anassembly line for further fabrication and assembly, while the layupmandrel 110 returns for cleaning and receiving another preform for acomposite part. In one embodiment, the layup mandrel 110 is alsoreworked (e.g., refilled with potting compound to restore layup contour112 as needed after drilling or cutting overshoot into potted areas ofrecesses 118 prior to demold, repaired, etc.) and transported to start alayup start location, such as on a wing panel layup line.

The method may then continue. For example, and as described in greaterdetail herein, the resulting composite part 250 may be indexed to a workstation in an assembly line via the indexing features 210, and work maybe performed on the composite part at the work station while thecomposite part is indexed to the work station. In some embodiments, thecomposite part 250 is suspended or otherwise conveyed through theassembly line by a shuttle, such as a strongback. The composite part 250may be indexed to the shuttle, such as by means of a correspondingindexing unit on a strongback. The strongback may in turn index to awork station, in which case the composite part may be said to be indexedto the work station via the strongback. In any case, the indexingcharacterizes to a work station at least a portion of the composite part250 (and/or the strongback) within the purview of the work station. Infurther embodiments, multiple indexing features interact with multiplework stations and/or with the strongback. The indexing may occur for oneor more work stations, until eventually the manufacturing excess 204 istrimmed from the composite part 250 (e.g., after indexing featureslocated in the manufacturing excess are no longer being used forassembly). After trimming, the composite part 250 has its finalperimeter 202, and the indexing features 210 in the manufacturing excesshave been removed. The composite part 250 is then integrated into a wingassembly of an aircraft.

Method 300 provides a substantial advantage over prior techniques,because it enables indexing features 210 to be installed into acomposite part 250 during layup, by reference to surface features 114 ona mandrel 110 that has been precisely toleranced. This eliminates theneed for the preform 200 to be precisely measured in order to installindexing features 210, because the indexing features are already placedat precisely known locations by virtue of the placement of the surfacefeatures and placement relative to the layup mandrel 110. The precisionof the layup mandrel 110 and layup processes is therefore leveraged toavoid the need for downstream contour scanning and indexing. Theprecision of the layup mandrel 110 is therefore extended/leveragedbeyond just layup processes to include post hardening processes such astrimming, milling or drilling to add indexing features prior to thedemold of the composite part 250. Therefore the accuracy relationship ofmultiple surface features 114 and correspondingly formed indexingfeatures 210 placed into the composite part 250 by using the layupmandrel 110 is carried along as the composite part advances, which mayenable fabrication processing steps to occur simultaneously on the samepart.

An example diagram showing how different feeder lines and assembly orlayup lines can be coordinated in an assembly line for assembling, forexample, a wing assembly, is shown in FIG. 4. FIG. 4 is a flow diagramillustrating an example of a schema, shown as schema 480 for feederlines 490 and assembly/layup lines 491, in an illustrative embodiment.Schema 480 provides a detailed example flow diagram for wing fabricationpertaining to feeder lines and takt times. All of the feeder lines, fromlayup material feeder lines through join operations for integratingwings to fuselage sections, are depicted, for a particular embodiment.In addition, each step indicated by an arrow is performed according to adesired takt time based upon the takt time of the component that itfeeds into.

In this embodiment, each feeder line is designated with a differentreference number 490 (e.g., 490-1, 490-2, etc.), and each assembly orlayup line is designated with a different reference number 491 (e.g.,491-1, 491-2, etc.). More specifically, a feeder line 490-1 provideslayup material to a wing panel layup line 491-1. A feeder line 490-2provides layup material to a spar layup line 491-5. A feeder line 490-3provides layup material to a rib layup line 491-3, and a feeder line490-4 provides layup material to a stringer layup line 491-2. Also,layup lines feed into other layup lines. Rib layup line 491-3 feeds intoa rib post-fabrication line 491-7, wing panel layup line 491-1 feedsinto a wing stringer placement line 491-4, and spar layup line 491-5feeds into a spar post-fabrication line 491-6.

Each feeder line is shown to have a takt time that facilitatesfabrication of the component that it fabricates. The takt times betweenfeeder lines and the assembly lines that they feed are synchronized toprovide just in time (“JIT”) delivery of components to the respectivework station 520, or work stations 520, that use those components (e.g.,as consumable goods, as inputs to a product being manufactured, etc.).The resulting component moves along assembly line 500 with work stations520 and is also progressed at a takt time. Each of the feeder line 490-1through 490-9 and or lines 491-1 through 491-9 takt times can be thesame, or some may be the same, or all can be different. Each feeder line490-1 through 490-9 progresses at a common takt for that particularline.

The takt time for each feeder line may be dependent upon a desiredproduction rate for an assembly line that the feeder line feeds. Forexample, if ribs are attached at a rate of one per hour and are attachedby two hundred fasteners, then two hundred fasteners should be suppliedto a rib install station per hour by a feeder line, resulting in afastener takt time of three and one third fasteners per minute.

In this embodiment, for example, rib layup line 491-3 progresses at atakt7 time and feeds into rib post-fabrication line 491-7. Wing panellayup line 491-1 progresses at a takt3 time and feeds into wing stringerplacement line 491-4. Spar layup line 491-5 progresses at a takt5 timeand feeds into spar post-fabrication line 491-6.

The rib post-fabrication line 491-7 progresses at a takt6 time, wingstringer placement line 491-4 progresses at a takt2 time, and sparpost-fabrication line 491-6 progresses at a takt4 time. All feed into awing assembly line 491-8, which progresses at a takt1 time and alsoreceives access port covers from access port cover feeder line 490-5,receives miscellaneous materials from miscellaneous material feeder line490-6, receives fasteners from fastener feeder line 490-7, and receivessealant from sealant feeder line 490-8. The wing panel 550 is hardenedin the autoclave in line 490-10. The composite part 250 is then trimmedand (in some embodiments) indexing features 210 are added prior toseparation from mandrel 110, for example in a demolding station, in line490-11. Trimmed excess material is removed from the wing assembly line491-8 via down chute 490-9. After fabrication is completed for a wing,line 491-9 moves the wing towards a fuselage for joining. Each of thevarious lines discussed above may provide material and/or a componentjust in time to the line that it feeds, at whatever rate may be desired.The takt time of the downstream line may or may not be equal to the lineor lines feeding it. Each line may have a unique takt time.

Any of the assembly lines, including feeder lines, can operate as micropulse, full pulse, and/or continuous lines with the fabrication processproceeding from left to right (relative to schema 480), with the varioustakt times synchronized for JIT delivery of components and/or materialsat the next line downstream. As used herein, a “pulse” refers toadvancement of a component in a process direction through an assemblyline followed by a pause. A component can be “micro pulsed” (a term thatherein refers to advancement of a component in the process direction bya distance that is less than its length) or can be “full pulsed”(advancement of a component by a distance equal to or more than itslength). As a part of pulsed fabrication, components in an assembly lineare pulsed synchronously, and multiple work stations can perform work ondifferent portions of the components during the same pauses betweenpulses, or during the pulses themselves. Phrased another way, thestations each perform work on a portion of the wing panel at the sametime, such that each station performs work on a different portion duringa pause in advancement of the wing panel along the track.

This parallel processing significantly increases work density within thefactory. The takt for each of the micro pulsed or fully pulsedcomponents can be the same or different, or a defined fraction of a takttime for another assembly line that receives the component. For example,a takt time at feeder line 490-2 for layup material for a spar may bedifferent for a takt time at feeder line 490-1 for layup material for awing panel, which may be different for a takt time for sealant providedvia sealant feeder line 490-8. In one embodiment, the takt time isconstant for each illustrated segment.

As noted above, the individual feeder lines discussed herein may bepulsed or continuously operated. Pulsed lines may implement micropulses, wherein the components being fabricated are advanced by lessthan their length before receiving work from a work station during apause, or may be full pulsed, wherein the components are advanced by anamount equal to their length. Furthermore, the various components (e.g.,wing assemblies, wing panels, ribs, spars, etc.) can be fabricated fromcomposite parts, or via additive or subtractive manufacturing techniquesfor metals. For example, in one embodiment, ribs are fabricated viasubtractive manufacturing of metal components at rib post-fabricationline 491-7, while wing panels are fabricated as composite parts (e.g., apreform) at wing panel layup line 491-1.

Various aspects of the schema illustrated in FIG. 4 and described abovemay be implemented in any fabrication setting, for example on a factoryfloor and/or in an assembly line for a wing, such as to coordinate thetiming of assembly, movement (e.g., pulsed and/or continuous), and/ordelivery of components and supplies, and/or other operations, on a JITbasis, or otherwise. Concordantly, the illustrative embodiments of anassembly line, such as the assembly line 500 depicted in FIGS. 5A-5F anddescribed below corresponds to assembly line 491-8. However, otherassembly lines and manufacturing processes consistent with thisdisclosure, may implement such a schema, or any aspects thereof, even ifnot specifically mentioned in the description of the embodiments.

FIGS. 5A-5F depict various aspects of an example assembly line 500 for awing in an illustrative embodiment. The assembly line 500 may beutilized to perform work upon wing panels, such as a wing panel 550,fabricated via the techniques and systems provided above in FIGS. 1-4.The description of FIGS. 5A-5F, as well as of the structures,components, and operations illustrated therein, are provided withrespect to a wing panel, but are applicable to any composite part. Thewing panel 550 is somewhat generically described, and may be an upper orlower, or right or left, wing panel. Where operations or featuresspecific to a certain type of wing panel 550 are described (e.g., anupper wing panel), the wing panel will be indicated as such. Theassembly line 500, a top view of which is shown schematically in FIG.5A, includes a track 510, along which a shuttle, shown in the form of agroup of three strongbacks 540, travels in a process direction 541(e.g., in a pulsed fashion from station-to-station, or continuously).The track 510 comprises one or more rails, rollers, or other elementsthat facilitate motion (e.g., rolling or sliding) of the shuttle alongthe track 510. The track 510 is capable of being mounted to a floor,suspended from above, etc., depending on the specific environment inwhich it is used. In the illustrated embodiment, the track 510 isdisposed above the various stations, and the shuttle (strongbacks 540)carries the wing panel 550 in the process direction. In particular, ascan be seen in FIG. 5D, a strongback 540 is shown to include adapters543, which mate with track 510 and enable locomotion via the track 510.For example, the adapters 543 may drive a strongback 540 along the track510, or may enable the track 510 to drive a strongback 540. Either way,this configuration is intended to broadly encompass any suitable mannerof structure designed to convey the wing panel 550 in a processdirection 541. In further embodiments, the track 510 includes a chaindrive, motorized cart, or other powered system (not shown) that iscapable of moving the strongback 540 in the process direction 541.

One or more strongbacks 540 advance a wing panel 550 through a varietyof work stations, generally designated at 520, that perform work on thewing panel 550. In FIG. 5A, three strongbacks 540 cooperate to carry asingle wing panel 550. However, a greater or fewer number of strongbacks540 may be used, as suitable. For convenience, the term “strongback”herein refers generally to a single structure that is configured toextend over a transverse section of a wing panel 550, such as achordwise section, although for convenience the term may be used hereinto refer generally to a shuttle that includes a plurality of suchstructures. When two or more strongbacks 540 cooperate to carry acomponent such as a wing panel 550, they may be coupled to each other(not shown) in a manner that maintains their constant relative position,so that only one strongback 540 is driven along the track 510. In such amanner, wing panels 550 of different lengths may be carried throughassembly line 500, such as by coupling a suitable number of strongbacks540 together in order to support the entire length of the wing panel550.

In some embodiments, indexing features of the wing panel 550, such aslocated in the manufacturing excess, may be used to index the wing panel550 with the strongback 540 that supports it. In the view in FIG. 5B,which corresponds with view arrows “5B” in FIG. 5A, strongback 540 isshown to include an indexing unit 542, which is configured to interfacewith corresponding indexing features installed in a manufacturing excess554 of the wing panel 550 (which may correspond to manufacturing excess204 of a preform 200 that was hardened into wing panel 550, per thefabrication process described above). In the illustrated embodiment, theindexing unit 542 physically couples with an indexing feature, in thatthe indexing unit 542 is shown to include a head 549 that is receivedwithin indexing features 210-1, which is shown as a through-hole.Although only one indexing unit 542 is shown in FIG. 5B, each strongback540 may include any suitable number of indexing units, each of which maybe configured to couple with an indexing feature 210 of the wing panel550, such as to initially align, and/or maintain alignment of, thestrongback with the wing panel. Like the indexing features 210, theindexing units 542 may take any suitable configuration, and may includecoupling means other than to enable a mechanical coupling, such asmagnets, and so forth. The indexing units may be configured to couplewith a variety of different indexing features 210, or indexing featuresthat may vary in location from one wing panel 550 to another, forexample to enable the strongback 540 to couple with different wingpanels, as needed.

In FIG. 5A, the work stations 520 of assembly line 500, are shown toinclude a non-destructive inspection or NDI station 524, a cut-outstation 526, a rib install station 528, and a spar install station 530.These work stations, as well as the operations performed at each, aswell as other illustrative work stations, are discussed in greaterdetail below. Other embodiments may include different work stations thanthose shown, work stations disposed in a different order, multiples ofone or more types of work station, and so forth. For example, in someembodiments, a fastener sealing station is utilized to seal the wing,and work stations are also included for installing electricalcomponents, electrical equipment, and/or fuel tank related systems.

As can be seen in FIG. 5A and more clearly in FIG. 5B, during work atthe various work stations 520 such as NDI station 524, the wing panel550 remains suspended beneath strongback 540 by carriers 545 (e.g.,independently adjustable components such as telescoping carriers, alsoreferred to herein as pogos) that include vacuum couplers 548, whichapply a removable vacuum connection to the wing panel in order to affixto the wing panel underneath the strongback 540). The view in FIG. 5Bshows four carriers 545, three of which are shown to have their vacuumcouplers 548 positioned against the upper surface 574 of the wing panel550, and one of which is shown to be in a shortened configuration sothat its vacuum coupler 548 is spaced from the upper surface of the wingpanel. Referring briefly to FIG. 5A shows that a different number ofcarriers 545 are used for each of the three strongbacks 540 thatcollectively support wing panel 550, with the carriers linearly disposedalong the width of the wing panel. However, any number and/orconfiguration of carriers 545 may be used. The carriers 545 are alignedto each contact the wing panel 550 at a predefined location and heighton the wing panel 550. Each carrier is rigid, once set to a desiredlength. Accordingly, the carriers 545, or more particularly thealignment of the carriers 545 relative to each other and their lengthsrelative to the wing panel 550, may be arranged to impart forces whichare transferred through the wing panel 550, and enforce a desiredcontour 544 into the wing panel 550. Thus, the strongback 540 suspendsthe wing panel 550 beneath it while enforcing a contour 544 onto thewing panel. This contour 544 may be that imparted to the wing panel bylayup mandrel 110 (e.g., contour 112 as shown in FIG. 1), or a differentcontour required for a specific application. Thus, while the strongback540 advances along the track 510 in a process direction 541, the contour544 is enforced by holding each carrier 545 at a desired height, whichforces a geometry at the wing panel 550 that corresponds with thecontour 544.

The attachment mechanism shown in the illustrated embodiment, as can beseen in FIG. 5B, is one in which carriers 545 engage with an uppersurface 574 of the wing panel 550, to form a vacuum grip between thevacuum couplers 548 of the carriers and the wing panel 550. The lengthof the carriers 545 is controlled by actuators 546, such as hydraulic orpneumatic actuators, or linear actuators. For example, one of carriers545 is shown to be in the process of being shortened, as indicated byarrow 1000. The carriers 545 may have their length adjusted, forexample, before a vacuum attachment is formed (for example, in order tofacilitate initial alignment for the vacuum couplers 548), and/or aftervacuum attachment is formed (in order to bend the wing panel 550 into adesired shape and/or enforce a desired contour upon the wing panel). Insome embodiments, actuators 546 are controlled via controller 620.

Although the shape of the wing panel 550, including the contour andcurvature thereof, is determined during layup and hardening, contourenforcement and adjustment may be desired after the wing panel has beendemolded. Contour enforcement, ensures that the wing panel 550 maintainsa desired shape and does not assume an undesirable contour, such as fromsagging under its own weight. In some embodiments, the contour enforcedby strongback 540 and carriers 545 facilitates installation of ribs andspars onto the wing panels, such as by ensuring proper alignment betweenthe component and the portion(s) of the wing panel to which thecomponent is to be installed. Specifically, the carriers 545 enforceboth chordwise and spanwise contours to a desired level of tolerance. Inone embodiment (not shown), the carriers 545 are capable of movingrelative to the strongback to predefined positions, in order to enforcecontours for a variety of wing shapes. Moreover, the “upper surface” 574to which carriers 545 attach, may be the exterior surface of a wingpanel 550 that is oriented “right side up” relative to strongback 540,or may be the interior surface of a wing panel that is inverted,according to whichever orientation is preferable for contour enforcement(and/or other operations as the wing panel 550 proceeds through theassembly line 500).

During the discussion of assembly line 500 and the operations performedby the various stations 520, intermittent references will be made tovarious flowcharts presented in the drawings (e.g., FIGS. 6-10) thatillustrate methods in accordance with the components and operationsillustrated in FIGS. 5A-5G. For example, FIG. 6 is a flowchartillustrating a method 800 of carrying a wing panel 550 in anillustrative embodiment. According to method 800, step 802 includesaligning a strongback 540 over a wing panel 550. In some embodiments,this comprises driving a strongback 540 along the track 510 until it ispositioned over a desired and/or predetermined transverse portion of thewing panel 550, such as a chordwise portion. In some embodiments, thiscomprises driving multiple strongbacks 540 until they are eachpositioned over different desired and/or predetermined transverse (e.g.,chordwise) portions of the wing panel 550. In one example, onestrongback 540 may be moved along the track 510 until it is positionedover a different portion of the wing panel 550 than another strongback540 that remains stationary. In some embodiments, aligning thestrongback 540 is performed by, or includes, indexing the strongback 540to the wing panel 550. In some of such embodiments, this indexing isdone by coupling the strongback 540 with one or more indexing featuresof the wing panel 550, such as by physically coupling an indexing unit542 of the strongback 540 with a corresponding indexing feature 210 ofthe wing panel 550. Indexing the strongback 540 with the wing panel 550in this manner may maintain the strongback and the wing panel in properalignment, such as throughout the subsequent actions of the method.

Step 804 includes forming a vacuum attachment between an upper surface574 of the wing panel 550 and vacuum couplers 548 of pogos 545 extendingbeneath the strongback 540, thereby coupling the pogos 545 to the uppersurface 574 of the wing panel 550. In one embodiment, this comprisesextending each of the pogos 545 until vacuum couplers 548 of the pogosphysically contact the upper surface 574 of the wing panel 550. In afurther embodiment, the pogos are attached systematically from themiddle of the wing panel 550 (e.g., chordwise or spanwise) and thenmoved outward, attached systematically starting with the pogo that is ata most out-of-contour location on the wing panel, or attached all atonce, and so forth.

As described in greater detail below, the positions of the pogos 545along the surface of the wing panel 550 may be determined by a varietyof factors, one of which is the manner in which the pogos, and thestress and/or strain forces imparted thereby, can cooperate in differentpossible configurations to enforce the predetermined contour to the wingpanel. There are, however, other competing factors. As one example, asdetailed below, inspection of the wing panel 550, such as vianon-destructive inspection (NDI) scanning may require an NDI inspectionhead to be positioned at, or moved over, one or more specific locationson the wing panel 550. Because the pogos can be selectively retracted,this can be accommodated either by temporarily retracting a pogo 545 toallow NDI inspection of the location on the wing panel 550 to which thevacuum coupler 548 is coupled, or by initially attaching the pogos tothe wing panel only at locations that will not interfere with NDIinspection. As another example, attachment of ribs and spars to thelower surface 576 (e.g., an interior surface) of wing panel 550 mayinvolve fastening operations (e.g. drilling) to occur at correspondinglocations on the upper surface 574 of the wing panel. As such, thepositions of the pogos 545 may be located so as not to interfere withsuch operations. Accordingly, the positions of the pogos 545 mayoptimize some or all of these (and/or other) considerations.

The coupling applied is the result of drawing a vacuum between thevacuum coupler 548 and the wing panel 550, and more specifically asurface thereof, such as upper surface 574. The amount of vacuum forceapplied over a portion of the wing panel 550 is sufficient to grip andhold the wing panel, and is also enough to flex the wing panel and holdit according to a desired contour 544. Specifically, the volume betweenthe carrier 545 and the wing panel 550 is evacuated to a pressure thatpermits the atmospheric pressure around the vacuum coupler 548 to causethe carrier 545 to removably adhere to the wing panel 550. The vacuumremains applied via the carriers 545 during transport, including duringpulses and pauses.

Step 806 includes adjusting lengths of the pogos 545 to enforce apredetermined contour onto the wing panel 550. That is, after the vacuumattachment is formed, the length of the pogos 545 is adjusted (e.g., viapressure, actuators, etc.) to conform wing panel 550 with a desiredcontour 544. In the illustrated embodiment, the pogos 545 areindependently adjustable. That is, depending on a position of each pogo545 along the length and width of the wing panel 550 (e.g., asdetermined via manual or laser-assisted processes), and depending on thedesired contour, the pogo is adjusted to a desired length. If the wingpanel 550 is already in conformance with the desired contour, then noadjustment or only minor adjustment to the length of one or more pogos545 may be performed. Alternatively, if the wing panel 550 is not inconformance with the desired contour (e.g., not within tolerance), thenadjusting the length of the pogos 545 bends or contours the wing panel(e.g., by applying a desired amount and direction of strain) in order tohold the wing panel in a desired shape.

In some embodiments, scanning is performed to determine an initial wingpanel contour. It is possible that no changes in the contour need to beenforced if a wing panel 550 is already at a desired (e.g.predetermined) contour initially, either across the entire wing panel orone or more portions thereof. In some of such embodiments, adjustmentsto the length of each pogo 545 (i.e., longer or shorter) relative to thestrongback 540, push and/or pull the wing panel 550 into a desiredcontour. Adjustments to the length of each pogo 545 is based at least inpart by a determination of the extent to which the wing panel 550 is outof alignment with the desired contour. That is, the length of some ofthe pogos 545 may require adjustment, whereas the length of others ofthe pogos 545 may not (e.g., if only some of the sections of the wingpanel 550 are not aligned with the predetermined contour). The locationof the vacuum couplers 548 of the pogos 545 are precisely locatedrelative to the upper surface 574 of the wing panel 550 to ensure thatwhen the pogos are at the desired length, the contour enforced by thepogos corresponds with expectations.

The length of the pogos 545 may be adjusted on the fly (e.g., byadjusting air logic applied to a pneumatic actuator controlling length,adjusting a hydraulic actuator controlling length, etc.) to align thepogos for establishing a vacuum attachment in a first phase (e.g., step804), and then enforcing a contour in a second phase (e.g., step 806).This facilitates length adjustment during initial attachment because ifthe pogos 545 are set rigidly to a particular length based on anexpected shape of the wing panel 550, then the vacuum couplers 548 maynot be able to form a vacuum attachment if the wing panel is out ofcontour (i.e., because the pogos are too long or short).

In some embodiments, scanning is performed to determine whether the wingpanel 550 is in the predetermined contour. This may be done while thelength of the pogos 545 are being adjusted, or after all of the pogoshave been adjusted.

The method may then continue, for example to advance the wing panel 550while the contour is enforced, such as by moving the strongback 540along track 510 in a process direction 541, and/or performing work onthe wing panel while the contour is enforced, such as at the variousstations 520. In embodiments in which scanning is performed, the methodmay include contour scanning during or after work operations areperformed, for example to ensure that the wing panel 550 remains in thedesired contour—or, in other words, that the wing panel has not becomeout of alignment with the predetermined contour as a result of the workoperations.

Returning to FIG. 5A, stations 520 disposed along the track 510 performwork on the wing panel 550, and may all operate at the same time (or atoverlapping times) as each other, or synchronized with one or moreothers, to perform different tasks at different sections of the wingpanel 550 (e.g., in the wing root section 577, mid length section 578,wing tip section 579, etc.). In this embodiment, NDI station 524inspects the wing panel 550 for out-of-tolerance conditions (e.g.,internal voids, foreign object debris or FOD, edge delamination orinconsistency, etc.), cut-out station 526 cuts access ports into thewing panel 550 (e.g. in manufacturing excess 554), rib install station528 mounts ribs to the wing panel 550, and spar install station 530installs spars to the wing panel 550.

In this embodiment, as will be explained in greater detail below, ribsare attached to the wing panel 550 during micro pulse advancement. Thiscan comprise multiple work stations operating on each rib at once, ormultiple work stations each operating on different ribs during the sameperiod of time. The spars are later attached while the wing panel 550 isretained at a full pulse work station 520. However, depending on theembodiment, the spars are attached before the ribs, or could beinstalled in a full- or micro-pulse process. The ribs are attached tothe wing panel 550 and spar using either micro pulsed or full pulseassembly. Alternatively, the wing panel 550 is lowered into positionover ribs which are then attached, and spars are pulsed to the wingpanel 550.

In one embodiment, the rib and spar installation processes are performedby providing ribs and spar segments in a JIT manner from parallel feederlines, such as by means of feeder lines similar to continuous rib feederline 491-7 and continuous spar feeder line 491-5, respectively, as shownin schema 480 in FIG. 4. Feeder lines are individually shown in FIG. 5Awith a different reference number 570 (e.g., 570-1, 570-2, etc.). Thesefeeder lines may be the same as, similar to, or different from, thevarious feeder lines 490 shown in schema 480, in terms of the materialsor components provided, the takt time according to which the feeder lineprovides materials or components, etc. In one embodiment, several sparsegments may be coupled, e.g. end-to-end, to form a spar. In furtherembodiments, there are several rib install stations along with one ormore fastener sealing stations and a plurality of spar install stations.Another embodiment has each spar comprising three segments that arespliced together at the ends of a rib.

The stations 520 are disposed along the track 510 and may be separatedby less than the length of wing panel 550 or even a portion thereof. Inone embodiment, such an arrangement enables multiple stations, such asNDI station 524, cut-out station 526, and rib install station 528, toperform work on the wing panel 550 simultaneously or overlapping intime. In further embodiments, the stations are distanced and/orotherwise configured such that only one work station at a time performswork on the wing panel 550.

As discussed in further detail herein, after proceeding through the workstations 520 shown in FIG. 5A, the wing panel 550 (which may be an upperwing panel, to which ribs and spars may be installed) enters a paneljoin stage, shown as panel join station 599 in FIG. 5F, that attachesanother wing panel (which may be a lower wing panel) to form a completedsection of airframe (e.g. a wing assembly) for a wing. The panel joinstage operates alone (e.g., by itself on the entirety of the wing,without other stations operating) after a wing panel 550 halts at thepanel join station 599 for fastening. In one embodiment, the pausing ofthe wing panel 550 at the panel join station 599 lasts while other wingpanels are pulsed through the work stations, until the other wing panelshave advanced by at least their entire length.

In the illustrated embodiment, feeder lines 570-1 through 570-6correspond, at least in part, to feeder lines 491-7, 491-4, and 491-5.Feeder lines 570-1 through 570-6 provide resources and components on ajust in time (JIT) basis to the various work stations 520 discussedabove, and their operations are controlled and/or synchronized bycontroller 560 (or additional controllers 560) according to a desiredtakt time. In one embodiment, feeder line 570-1 corresponds at least inpart to access port cover feeder line 490-5, and provides newlyfabricated access hole covers to cut-out station 526. Feeder line 570-2provides fasteners to cut-out station 526. Feeder line 570-3 providesfasteners to spar install station 530. Feeder line 570-4 providessealant to spar install station 530. Feeder line 570-5 providesfasteners to rib install station 528, and feeder line 570-6 providessealant to rib install station 528. In further embodiments,additional/other feeder lines provide newly fabricated ribs, fasteners,and sealant spars, lower panels, etc. to various work stations.

In one embodiment, an upper wing panel proceeds through the workstations 520 shown in FIG. 5A, and is followed by a lower wing panel. Asbriefly noted above, the lower wing panel does not receive ribs or spars(i.e., because these components are already installed to the upper wingpanel). As will become clear, cut-out stations, such as cut-out station526, perform a majority of the work on the lower wing panel, while amajority of work on the upper wing panel consists of installing ribs andspars.

Each station 520 in the assembly line 500 is designed to physicallycouple, to image, and/or to otherwise interact with an indexing feature210 in the wing panel 550, or with a strongback 540 that is itselfphysically coupled with an indexing feature 210. The indexing features210 are placed at desired locations along the wing panel 550. In someembodiments, the indexing features are aligned along the wing panel 550.In some embodiments, the indexing features are not aligned. In someembodiments, the indexing features are equally spaced, and in someembodiments, the indexing features are not equally spaced. In someembodiments, the number of indexing features is equal to the number ofwork stations in the assembly line. In some embodiments, there can bemore or fewer indexing features 210 than work stations at the assemblyline. The indexing features 210 are disposed in a manufacturing excess554 of the wing panel 550, which is trimmed away prior to a wing beingassembled into an airframe for a fuselage.

In this embodiment, each of the stations 520 in the assembly line 500inserts into, grasps, fits, or aligns to an indexing feature 210. Inaddition to (or instead of) a physical (e.g. mechanical) coupling,indexing in some embodiments may be facilitated or accompanied byreading an RFID chip and/or other readable identifying means 126 (e.g.,a bar code, etc.) on the wing panel. An illustrative example of aphysical coupling is shown in FIG. 5B, which shows a section of the wingpanel 550 within NDI station 524. Among the various structuralcomponents of NDI station 524 is an upper NDI unit 602, which includesan upper frame 614. Upper frame 614 is shown to include an indexing unit622. In a manner similar to that described above with indexing unit 542of strongback 540, indexing unit 622 of the NDI station 524 physicallycouples with an indexing feature of the wing panel 550, specifically bymeans of a head 624 that is received in indexing feature 210-2 locatedin a manufacturing excess 554, with indexing feature 210-2 shown as athrough-hole. Again, although only one indexing unit 622 is shown inFIG. 5B, each work station 520 may include any suitable number ofindexing units 622, each of which may be configured to couple with anindexing feature of the wing panel 550, such as to initially align,and/or maintain alignment of, the wing panel with the work station. Likethe indexing features, the indexing units 622 may take any suitableconfiguration, and may include coupling means other than to enable amechanical coupling, such as magnets, and so forth. The indexing unitsmay be configured to couple with a variety of different indexingfeatures, or indexing features that may vary in location from one wingpanel to another, for example to enable the work station(s) to couplewith different wing panels, as needed.

In the illustrated embodiment, indexing feature 210-1 of the wing panel550 is shown to be coupled to an indexing unit 542 of the strongback540, whereas indexing feature 210-2 is shown to be coupled to anindexing unit 622 of the NDI station 524. This is intended to illustrateexample indexing configurations for the sake of explanation, rather thanto indicate that indexing a wing panel by means of a physical couplingto both the strongback and the work station is required to allembodiments. In some embodiments, one or more work stations index with astrongback supporting the wing panel instead of directly indexing withthe wing panel. In some embodiments, one or more work stations indexwith the wing panel 550 instead of with a strongback 540. In someembodiments, work stations index with both the wing panel and astrongback. In any of these embodiments, the strongback may also indexwith the wing panel.

When an RFID chip (or other readable identifying means) is used, forexample in addition to or as an alternative to another type of indexingfeature, an RFID scanner (or suitable reader) may couple to provideindexing when brought into communication at a work station. In furtherembodiments, the strongback 540 itself physically couples with theindexing features 210, RFID chip, and/or hard stops or other features toindex the strongback 540 to the work stations. During assembly, thestrongback 540 is coupled with/mounted for movement along track 510, andis pulsed (e.g., micro pulsed by less than a length of the wing panel550, according to a takt that may or may not be commonly shared withother assembly lines). In one embodiment, a limiting factor on takt isthe amount of time a portion of the wing panel 550 spends within thepurview of a particular work station, plus the pulse time. This time canbe adjusted by changing the work scope of the particular work station,or adding additional work stations to do the same work (such as multiplerib install stations 528 as opposed to only one), and so forth. Thepulses discussed herein may be implemented as a distance at least equalto the shortest distance between indexing features 210 (e.g., a pitchdistance between ribs, or “rib pitch,” or a multiple or a fraction of arib pitch, etc.) or full length or a fraction length of the wing panel550. In embodiments where pitch distance between ribs, and/or rib pitch,is used for pulse length, that can be used to establish a micro pulselength. The wing panel 550 can be continuously moved, and indexed to thework stations 520. Once indexed, work is then performed by the workstations 520. Whenever the indexing features 210 (and/or RFID chip) andthe strongback 540 are mated or otherwise in communication, thestrongback 540 is indexed to one or more of the work stations 520, andthe location of the wing panel 550 is indexed to a location in acoordinate space shared by the track 510 and known to the work stations.In a further embodiment, indexing also includes conveying a 3Dcharacterization of structure, such as of contour 544, within thepurview of the work station. For example, an RFID chip or other readableidentifying means 126 (e.g. a bar code) can convey informationindicating a geometry of the composite part being worked upon.

In one embodiment, indexing is performed at least according to a wingpanel 550 carried upon a strongback 540 that moves along a track 510comprising a rail system located above the work stations 520. The railsystem could be coupled to a gantry or a structure above the workstations such as a ceiling or to the floor such as embedded within thefloor, bolted to the floor, etc., or may be coupled to another portionof the factory. The wing panel 550 has been fabricated on a layupmandrel 110 according to precise dimensions as discussed above. Becausethe layup mandrel 110 has finely toleranced surface features, andbecause the preform 200 for the wing panel 550 was laid-up over andconformed to those surface features, the wing panel 550 includesindexing features 210 that are precisely located in a manufacturingexcess 554. Thus, once the wing panel 550 is indexed and suspended underthe strongback 540 and advanced to a work station 520, the 3D positionand rotation of the wing panel 550, including the contour 544, isconveyed by indexing and is precisely known at the work station 520.Indexing may thus remove the need, for example, for a full scan viaprobes or robust optical technology at each work station 520. Thisinformation is provided to the work station 520, as needed, as part ofthe indexing, for example, via information provided by an RFID chip.This allows one line to work in series on different parts for anaircraft, for example right and left upper and lower wing panels, oreven on different parts (e.g., wing panels) for different aircraftmodels. Thus, the characteristics of the wing panel 550 within thepurview of the work station 520 is conveyed to the work station as partof each pulse or micro pulse. As a wing panel has more variation frompulse location to pulse location than a fuselage panel, manufacturingexcess at the wing panel may include a larger number of surface featuresto facilitate indexing.

Because of the precise indexing performed, the positions of the tools ateach work station 520 relative to the wing panel 550, when indexed tothe work station, are precisely known. In some embodiments, the wingpanel 550 is locked into place at the work station 520. The 3D positionand orientation of the wing panel is then established or indexed intoany Numerical Control (NC) programming, or manual or automated system inuse at the work station. Therefore, no setup time or scanning may beneeded after each movement (e.g., pulse and/or micro pulse) of the wingpanel. Furthermore, structure added to or removed from the wing panel550 in the prior work station 520 may be added to whatever wing panelmodel or representation is within the system, without the need to scanthe wing panel for changes.

The operations of the work stations 520 are managed by a controller,generally indicated in FIG. 5A as controller 560. In one embodiment,controller 560 determines a progress of the strongback 540 along thetrack 510 (e.g., based on input from a technician), and uses this inputto manage the operations of the work stations in accordance withinstructions stored in an NC program. Controller 560 may be implemented,for example, as custom circuitry, as a hardware processor executingprogrammed instructions, or some combination thereof.

The following paragraphs discuss the operations of the various workstations 520 shown in FIG. 5A. As shown in FIG. 5A, in assembly line500, three work stations 520—specifically, NDI station 524, cut-outstation 526, and rib install station 528—are disposed along track 510 inclose enough proximity so that a wing panel 550 may encounter all threework stations as it progresses in process direction 541. Morespecifically, given the span-wise 590 length of wing panels 550 fromleading edge to trailing edge (e.g., a wing tip to a wing root, asoriented in the illustrated embodiment), different portions of a wingpanel may proceed through two or more different work stations 520 at thesame time. For example, wing panel 550 is shown positioned such that atrailing portion of the wing panel, shown as wing root section 577,encounters NDI station 524 at the same time that a leading portion,shown as a wing tip section 579, encounters rib install station 528, anda middle portion, shown as mid length section 578, encounters cut-outstation 526. As such, one, or two, or all three of these work stations520 may perform operations on the respective portion(s) of wing panel550 at the same time, or overlapping in time. In some embodiments, notall of these operations are necessarily performed at the same time, eventhough portions of the wing panel 550 are positioned in each workstation 520. In one embodiment, NDI is performed at NDI station 524 asportions of the wing panel 550 are pulsed through the work station.Thus, NDI occurs within NDI station 524 on only that portion of the wingpanel 550 within the work station at any one time.

FIG. 5B is a front view of NDI station 524 (and, as noted above,corresponds with view arrows “5B” in FIG. 5A), which is shown in theprocess of inspecting a wing panel 550, with wing panel 550 shown incross section, in the illustrative embodiment. FIG. 5B illustratesinspection techniques and systems that may be implemented, for example,prior to installation of ribs and spars onto the wing panel. FIG. 5Bdepicts a strongback 540 that suspends a wing panel 550 beneath it. TheNDI station 524 is disposed at the track 510, and inspects the wingpanel 550 while the wing panel 550 is suspended beneath the strongback540.

The NDI station 524 shown in FIG. 5B includes an upper NDI unit 602 anda lower NDI unit 604. Upper NDI unit 602 includes supports 612 and aframe 614 that carry one or more NDI inspection heads 606, shown asupper NDI inspection head 608, which is configured to move relative towing panel 550 and inspect the upper surface 574 thereof. Lower NDI unit604 of NDI station 524 is also shown to include a frame 618 and supports616 that carry additional NDI inspection heads 606, shown as lower NDIinspection heads 610, in a manner than allows the inspection heads toinspect the lower surface 576 of the wing panel 550. For simplicity, NDIinspection heads 606 are also referred to as “inspection heads,” orsimply “heads.” Inspection heads 606 may be mobile—that is, they may beconfigured to move relative to the upper NDI unit 602, the lower NDIunit 604, and/or the wing panel 550, or they may instead be stationaryor fixed. For example, in the illustrated embodiment, upper inspectionhead 608 is shown, via directional arrow 1002, to be in the process ofmoving relative to the upper surface 574 of wing panel 550, as enabledby a track and/or a drive or any suitable mechanism (not shown) of theupper NDI unit 602. Some or all of lower inspection heads 610 may alsobe mobile, in which case they may be independently moveable, configuredto move in unison as an array, and so forth, or they may be stationary.Further embodiments may include any number or configuration ofinspection heads other than as shown in FIG. 5B. Mobile inspection headsmay be used for surface inspection during pauses between advancements orother movements of the wing panel 550 relative to the NDI station 524,such as by individually traversing distinct areal portions of a surfaceof wing panel 550. Fixed inspection heads may be used for surfaceinspection as the wing panel 550 pulses or otherwise moves relative tothe NDI station 524. For efficiency, the arrangement of inspection heads606 relative to NDI station 524, and/or to the position(s) of the wingpanel 550 as it advances through the work station 520, may be one thatdisposes the inspection heads at locations of interest, for example atlocations where out of tolerance conditions are more likely to be found,such as those for which inspection of prior wing panels and/or analysisof prior wing panels indicates a need or desire for inspection, and arenot placed where there is less need for inspection. Other arrangementsof inspection heads may be used as desired or needed for a particularapplication. Some embodiments may include upper and lower inspectionheads disposed in pairs, on either side of the wing panel 550, such asto carry out through-transmission inspection techniques. In someembodiments, inspection heads 606 are disposed to inspect an entiresurface, or surfaces, of the wing panel 550. For example, in a furtherembodiment, fixed NDI inspection heads are placed such that theinspection occurs during the pulse, and the inspection heads aredisposed in order to cover the entire surface without the need for headmovement. This set up can be employed on both the upper and lowersurfaces and can be implemented with less complexity than systems whichutilize mobile heads. The inspection heads 606 discussed herein maycomprise ultrasonic transducers that transmit ultrasonic energy throughthe wing panel 550 in order to characterize internal features of thewing panel. The operations of the inspection heads 606 (e.g., both theupper inspection heads 608 and lower inspection heads 610) are managedby a controller, shown at 620, which operates an NC program tocoordinate the actions of the inspection heads to facilitate scanning ofthe wing panel 550 in a pulse-echo or through-transmission mode.Controller 620 may interface with, and be distinct from, controller 560.In some embodiments, controller 560 may provide the aforementionedfunctions of controller 620.

As noted above, NDI station 524 is shown in the illustrated embodimentto be physically indexed to the wing panel 550 by means of indexing unit622 of the NDI station, the head 624 of which is received withinindexing feature 210-2 of the wing panel 550.

Strongback 540 includes telescoping or adjustable-length carriers orpogos 545 which include vacuum couplers 548 configured to removeablyattach to upper surface 574 of the wing panel 550—forming a vacuum gripbetween the vacuum couplers 548 and the wing panel 550. As noted above,the length of the carriers 545, such as to impart or enforce a contourto wing panel 550, is controlled by actuators 546, such as hydraulic orpneumatic actuators, or linear actuators. Controller 620 may coordinatethe control of actuators 546. In some embodiments, controller 620coordinates control of actuators 546 with the operation of NDI station524, such as to allow inspection of the wing panel 550 in a manner thatavoids or accommodates vacuum couplers 548 coupled to the wing surface.In one such embodiment, the controller 620 directs the strongback 540 toselectively retract one or more of the vacuum couplers 548 by shorteningcorresponding carriers 545 to allow inspection head 608 of the NDIstation 524 to inspect portions of the upper surface 574 of the wingpanel 550 (such as portion 582) to which vacuum couplers 630 had beenattached. This is shown in FIG. 5B with the coordinated shortening ofone of carriers 545 to retract its vacuum coupler 548 from portion 582,indicated by directional arrow 1000, with the movement of upperinspection head 608 toward portion 582, as indicated by directionalarrow 1002. When the NDI inspection of, for example, portion 582 iscompleted, the corresponding carrier 545 is extended such that itsvacuum coupler 548 is again vacuum connected to the upper surface 574 ofthe wing panel 550. In a similar manner, other portions of the uppersurface 574 of wing panel 550 that are obscured by a vacuum coupler 548may be systematically inspected. Of course, such a configuration is notrequired to all embodiments. For example, in further embodiments, theinspection heads 606 are routed around the carriers 545 and vacuumcouplers 548, which are not retracted during NDI inspection. In furtherembodiments, the contour of wing panels 550 vary from type of wingpanel, or of wing panel for different models, and the carriers 545 aretherefore extended to different positions/extensions depending on thecontour of the wing panel.

In further embodiments where a strongback 540 is used, inspectinglocations on the wing panel 550 that contact the strongback (e.g., bymeans of pogos 545 and vacuum couplers 548) via NDI is performed priorto suspending the wing panel beneath the strongback.

FIG. 7 is a flowchart illustrating an embodiment of method of inspectinga wing panel, designated as method 820. Method 820 progresses in aseries of steps that include actions described with reference to thecomponents and structure shown in FIG. 5B, as well as in FIGS. 1-4 and5A. Method 820 is shown to begin with step 822, which includessuspending a wing panel 550 beneath a shuttle, such as strongbacks 540.In one embodiment as discussed above, suction is applied via theretractable vacuum couplers 548 to hold the wing panel 550 in positionand to enforce a desired contour 544 onto the wing panel 550.Specifically, the vacuum coupling of a vacuum coupler 548 along with theinflexibility of the strongback 540 and the extendability of pogos 545allows contour enforcement to be performed on the wing panel 550. Thepogos 545 are removably coupled to the wing panel 550 in order tomanipulate it into a desired contour.

Step 824 includes advancing the wing panel 550 in a process directionthrough an NDI station 524 via the shuttle. In embodiments in which theshuttle is a strongback 540, this includes driving the strongback 540along a track 510 as described above for earlier methods, and may beperformed via pulsed or continuous movement techniques. In embodimentsin which the shuttle takes another form, e.g. a cart, an AutonomousGuided Vehicle (AGV), and so forth, this step comprises driving theshuttle along a rail or appropriate pathway.

Step 826 includes inspecting the wing panel 550 via the NDI station 524while the wing panel 550 is suspended beneath the strongback 540. In oneembodiment, this includes performing pulse-echo techniques (e.g., viaone or more individual inspection heads 606), or through-transmissiontechniques (e.g., via pairs of inspection heads 606 arranged on eithersurface of the wing panel 550). These arrangements detect differences intiming from expected values as ultrasonic energy travels through thethickness of the wing panel 550. This may comprise operating an array ofinspection heads 606 at the NDI station 524 at once. Detecteddifferences in timing are analyzed by the controller 620 to determinewhether or not an out-of-tolerance condition exists that necessitatesrework of the wing panel 550. Rework may be accomplished at a dedicatedwork station downstream of the NDI station 524. That is, controller 620detects out-of-tolerance conditions at the wing panel 550 based on inputfrom the NDI station 524, and reports the out-of-tolerance conditionsfor rework (e.g., via a notification provided to a technician). In afurther embodiment, the controller 620 controls the NDI station 524, andcontrols advancement of the wing panel 550 in the process direction, andrelates input from the NDI station to locations on the wing panel 550.

As noted above, in some embodiments, inspection involves selectivelyretracting one or more vacuum couplers 548, such as by the strongback540, as one or more inspection heads 606 inspects a surface of the wingpanel, such as to allow inspection of the corresponding portions of thesurface otherwise obsctructed by the vacuum couplers. In furtherembodiments inspection is performed by arranging carriers 545 and/orotherwise placing vacuum couplers 548 at locations on the surfaces ofwing panel 550 where NDI inspection is not required, by inspectinglocations on the wing panel that contact the strongback 540—such as theaforementioned portions to which the vacuum couplers 548 connect—via NDIprior to suspending the wing panel beneath the strongback, and/or byoperating an array of inspection heads 606 to enable an entirety ofinspection to be performed without requiring single inspection heads tobe moved, and so forth.

As also noted above, the NDI station 524 may include NDI inspectionheads 606 that are mobile, or fixed, or a combination thereof. In someembodiments, the method includes disposing at least some of theinspection heads at locations of interest, such as those for which priorinspection and/or analysis indicates a need or desire for inspection. Insome embodiments, the inspection heads are located in order to enablethe inspection of the entirety of a desired portion of the wing panel550 (such as one or more entire portions thereof, or the entire wingpanel). In some embodiments in which the NDI inspection heads are fixed,advancing the wing panel 550 includes advancing the wing panel past thefixed inspection heads as they inspect the portion of the wing panel. Insuch embodiments, it may be said that step 824 and step 826 take placeat the same time, or overlap in time. In some embodiments in which theNDI inspection heads are mobile, advancing the wing panel 550 includesadvancing the wing panel past the mobile inspection heads. In some ofsuch embodiments, such as those in which advancing the wing panel 550includes pulsing the wing panel in a process direction, the inspectionis performed during pauses between the pulses and/or during the pulses.In some embodiments that include an array of inspection heads, themethod includes moving the inspection heads relative to the wing panel550 while operating the array. In any of these manners, the NDI station524 inspects a portion of the wing panel 550 at a time, as it isadvanced through the NDI station.

The position of the wing panel 550 relative to the NDI station 524, insome embodiments, is monitored by indexing the wing panel to the NDIstation, such as by means of various indexing features and/or RFIDchips, as noted above. In some embodiments, the indexing of the wingpanel to the work station, either directly or via a strongbacksupporting the wing panel, conveys information about the wing panel tothe NDI station controller, which in turn may direct NDI inspection ofthe wing panel based at least in part on this information. In someembodiments in which the indexing features are located in amanufacturing excess of the wing panel, the manufacturing excess istypically not inspected.

In some embodiments, the method continues with additional steps that arenot shown in FIG. 7. For example, the method may continue by advancingthe wing panel to the next work station (e.g., a cut-out station such ascut-out station 526, and so forth). In embodiments in which the wingpanel is suspended beneath a strongback, such a method may advance thewing panel to the next work station while the wing panel remainssuspended beneath the strongback. Some embodiments utilize multiple NDIstations for inspection, and some embodiments utilize the NDI station(or more than one NDI station) for NDI inspection of additionalcomponents. For example, in some of such embodiments, an NDI stationscans stiffener flanges while scanning the wing panel, and additionalNDI stations scan stringers attached to the wing panel.

Above, it is noted that in some embodiments, NDI inspection is performedas the wing panel is advanced past NDI inspection heads. This may bedone regardless of the manner of conveyance of the wing panel (e.g., viaa strongback or otherwise). FIG. 8 further depicts a method 840 ofinspecting a wing panel 550 in an illustrative embodiment. According toFIG. 8, step 842 includes receiving a wing panel 550 at an NDI station524. Step 844 includes inspecting a portion of the wing panel 550 viathe NDI station 524 during movement of the wing panel through the NDIstation. The wing panel may be pulsed or advanced continuously throughthe NDI station, with inspection taking place during movement of thewing panel through the NDI station. As with method 820, in method 840,the NDI station may include mobile and/or fixed NDI inspection heads. Inone embodiment the wing panel remains suspended beneath the strongbackwhile the wing panel is at the NDI station. In a further embodiment,mobile inspection heads of the NDI station individually traversedistinct areal portions of the wing panel via mobile inspection heads ofthe NDI station. In this manner, inspection includes moving inspectionheads relative to the wing panel while operating the array of inspectionheads at NDI station.

Returning to FIG. 5A, mid-length section 578 of wing panel 550 is shownto be within cut-out station 526. Broadly, cut-out station 526 isconfigured to remove material from wing panel 550, for example withinmanufacturing excess 554 or otherwise. In some embodiments, cut-outstation 526 cuts out one or more regions of wing panel 550, for exampleto install an opening such as an access port that will be utilized in awork station downstream, such as to provide access to the interiorvolume between wing panels after they have been joined together at ajoin station. Although not necessary to all embodiments, such accessports are typically installed in lower wing panels, as opposed to upperwing panels. As will become clear herein from the discussion relating toshimming operations (e.g., as shown and described with respect to FIGS.16A-16C and 17A-17C), in some embodiments, a lower wing panel isprovided with several access ports that provide access to bays betweenadjacent ribs, for example to facilitate shim installation by a robotarm. Thus, in such embodiments, cut-out station 526 may perform morework operations on a lower wing panel than on an upper wing panel. Ineither case, cut-out station 526 may install access port covers and/ordoors into the wing panel 550, along with edge sealing, painting, andperforming fastener drilling and installation, as suitable for the wingpanel. In some embodiments, edge trimming of the manufacturing excess,and trimming of an access port, are performed at different workstations.

The terms “upper surface” and “lower surface” of wing panel 550 are usedherein for convenience to indicate the relative orientations of theopposing surfaces of the wing panel as it is suspended below thestrongback 540, in the illustrated embodiment. However, as will becomeclear herein, additional components (such as ribs and spars) may beinstalled to the lower surface 576 of wing panel 550 as the uppersurface 574 thereof continues to be held by vacuum couplers 548 of pogos545, to produce a wing assembly 600. As such, the surface indicated inFIGS. 5A-5G as lower surface 576 of the wing panel 550 becomes what maybe thought of as an interior surface of a wing assembly 600, whereas thesurface indicated as upper surface 574 of the wing panel 550 becomeswhat may be thought of as an exterior surface of a wing assembly 600.Accordingly, the terms “upper surface” and “lower surface” are not to beconstrued in a limiting sense.

FIG. 5C corresponds with the top view of assembly line 500 shown in FIG.5A, but showing the strongback 540 as having advanced in the processdirection 541 so that the wing root section 577 of wing panel 550 iswithin rib install station 528. Some aspects of FIG. 5A (e.g., variousfeeder lines, and so forth) are not shown in FIG. 5C, for simplicity.FIG. 5D shows a simplified side view corresponding with view arrows “5D”of FIG. 5C, with some components that are visible in FIG. 5C omitted tobetter illustrate the ongoing construction/progress of the wing panel550 into a wing assembly 600. As noted above, rib install station 528affixes (that is, temporarily and/or permanently installs) ribs 572.Ribs 572 are shown in these views in simplified form for ease ofexplanation, although they are often more complex in configuration andappearance, as described in greater detail in sections below.

FIG. 5C also shows, in spar install station 530, that spars 580 haveadvanced from feeder lines (not shown) to the station 530. As notedabove, the supply of spars 580 to the spar install station 530 may becoordinated as just-in-time delivery for installation to a wing panel.Accordingly, FIG. 5C may show a state of assembly line 500 just beforewing panel 550 is moved to spar installation station 530 forinstallation of the spars 580, which have just been supplied to thestation.

FIG. 5C further illustrates the use of a mobile station 552 (also calleda “follower”), which is configured to couple to the wing panel 550 andstrongback 540 and perform work (such as trimming, installing fasteners,applying sealant, etc.) by traveling across the wing panel 550, forexample along a mobile station track 551 that may be removably installedonto the wing panel 550. Although not required to all embodiments,mobile station 552 may perform the work during pulses (e.g., micropulses), pauses (e.g., between micro pulses), or continuous motion ofthe wing panel 550 as it progresses through the assembly line 500.Depending on design, the mobile station 552 can “ride along” with (or“follow”) the wing panel 550 for multiple pulses across multiple workstations 520, and can operate independently of the other work stationsof the assembly line 500. During this process, the location anddimension of gaps (e.g. spacing) between strongbacks 540 enableplacement of the mobile station track 551 and/or mobile station 552. Infurther embodiments, chutes and other complementary elements aredisposed at the factory such that mobile station 552 passes over orthough these elements during fabrication processes. Mobile station 552may be removed along a return line, shown in FIG. 5C at 547, and sent,e.g. in a direction opposite the process direction 541 (e.g., upstreamin assembly line 500) to be installed on a next wing panel as desired.In further embodiments, one or more of strongbacks 540 form a “smartbridge” by dynamically moving relative to the wing panel 550, in orderto provide greater access to the wing panel 550 by the mobile station552.

As noted above, FIG. 5D is a simplified side view of a portion ofassembly line 500, showing wing panel 550 with attached ribs 572 beingtransported along track 510 while suspended below a set of threestrongbacks 540. As briefly noted above, one or more adapters 543 mayfacilitate the movement of strongbacks 540 along the track 510. The ribs572 are attached to a lower surface 576 of the wing panel 550 at asuitable angle, indicated as angle θ. As will be explained below, insome embodiments, ribs 572 are aligned vertically and raised intoposition for attachment to the lower surface 576 of the wing panel 550(or, more specifically, an upper wing panel). As such, the wing panelmay be suspended below the strongback(s) at an angle that corresponds toand/or facilitates the rib installation at angle θ. This is shown inFIG. 5D with the wing panel 550 tilted slightly upward from the wingroot section 577 to the wing tip section 579.

FIG. 5D also provides another view of an illustrative configuration ofpogos 545 and vacuum couplers 548. In the illustrated embodiment, thevacuum couplers 548 are capable of angular deflection relative to thepogos 545 and strongback 540. The angular deflection may be facilitatedby a universal type joint, either at the point at which vacuum coupler548 is coupled to the pogo 545 and/or at the point at which the pogo 545is coupled to the strongback 540. The angular deflection may accommodatecoupling to wing panel 550 during contour changes in the wing panel, tosuspend the wing panel at a desired angle (as shown), and so forth.Owing to the angular flexibility of the vacuum couplers, by adjustingthe pogos to appropriate lengths, the wing panel may be suspended at anydesired angle. In further embodiments, otherwise-configured carriers 545grip an upper surface 574 of the wing panel 550 (e.g., via clamping,interference fits, etc.). As explained in detail above, a desiredcontour can be enforced by adjusting the pogos 545 to predeterminedlengths, which correspond with a desired vertical loft of the contour ateach of multiple chordwise and spanwise locations.

As noted above, several factors may determine the positions of pogos545, and their respective vacuum couplers 548, relative to the uppersurface 574 of the wing panel 550, such as to enforce a contour to wingpanel 550. In some embodiments, one factor is the manner in which ribsand spars are attached to the wing panel. For example, the pogos 545 andvacuum couplers 548 may be placed so that the positions of the vacuumcouplers 548 on the upper surface 574 are spaced away from thecorresponding positions on the lower surface 576 of the wing panel whereribs 572 will be attached to the wing panel (as in the view shown inFIG. 5D). This may be done, for example, to allow fabrication access tothe rib 572 install area, and can facilitate either manual or automateddrill and fastener installation connecting ribs to wing panels.

In FIG. 5D, one rib 572 is shown attached to the portion of wing panel550 that is within rib install station 528. Other ribs 572, which areshown attached to the portions of wing panel 550 that have advanced pastrib install station 528, were installed when those portions were withinrib install station 528. Although four are shown, the number of ribs 572may be, and often are, greater in an actual wing assembly 600. The wingpanels, ribs, spars, and other components shown in FIG. 5D and the otherdrawings are for illustration purposes only and are not necessarily toscale or contour. For example, ribs 572 are shown in simplified,schematic form in this series of drawings. Later drawings, such as FIGS.11A-11D and FIGS. 17A-17C, show illustrative ribs in greater detail. Therib configuration or number of ribs 572 of an actual wing assembly 600may vary from that depicted herein.

FIG. 5E, a top view of assembly line 500 corresponding to those in FIGS.5A and 5C, illustrates the wing panel 550 having been transported viastrongbacks 540 to spar install station 530, wherein spars 580 areattached (e.g., as part of a full-pulse process). In this embodiment,the spars 580 are installed after the ribs 572, but in some embodimentsthe ribs 572 are installed prior to the spars 580. Also, FIG. 5E showseach spar, generally indicated at 580, as having been assembled from anumber of individual spar segments, each separately indicated as 580-1through 580-7 (however, unless specifically indicated otherwise,reference number 580 is used herein to refer to spars, as well as sparsegments or spar sections). Spar install station 530 may receivepreassembled spars 580, or individual spar segments or sections (e.g.,580-1 through 580-7) that are assembled at the spar install station, orboth, from one or more feeder lines 570 (a representative one of whichis shown in FIG. 5E). In embodiments in which spar segments are providedto spar install station 530, the spar segments may be assembled to eachother prior to installation to the wing panel, for example to form apartial or whole spar that is then installed to the wing panel, and/orthe spar segments may be installed as spar segments to the wing panel,forming a spar as they are separately installed. Additional componentssuch as fasteners, sealant, and so forth are also supplied to sparinstall station 530 to facilitate installation. After installation, thestrongbacks 540 transport the wing panel 550 back to track 510, and thewing panel 550 is further transported to receive additional work. In theillustrated embodiment, the strongbacks 540 progress to spar installstation 530 in any suitable manner, such as a redirect track (not shown)configured to allow movement to spar install station 530 in direction1004. After installation, the strongbacks may either progress indirection 1006 back to track 510 via the same redirect track, forexample for further progress along track 510 (e.g. toward a panel joinstation), or are directed to another track, or progress along a trackother than track 510. Another embodiment has spar install station 530disposed along track 510 so that advancement of a strongback 540 in theprocess direction brings a wing panel into, through, and out of thestation.

The illustrated configuration is an example of a configuration that mayallow a work station 520, such as spar install station 530, to beselectively bypassed. As noted above, in some embodiments, ribs andspars are attached only to upper wing panels, and not to lower wingpanels. In such embodiments, efficiency in transporting and/orperforming work on wing panels may be achieved in a configuration thatmay allow one or more work stations 520 to be selectively bypassed, suchas with upper wing panels being advanced into the spar install station530, but with lower wing panels being advanced past the station. In someof such embodiments, the lower wing panels may instead be directed to awork station configured for work specifically on lower wing panels, andnot on upper wing panels, such as a work station that cuts access portsinto the lower wing panel (for example, a work station such as cut-outstation 526). In these embodiments, additional spars and/or sparsegments are then fed to spar install station 530 for attachment to anext wing panel 550 traveling along the track 510.

FIG. 5F illustrates an embodiment wherein, after work is complete atspar install station 530, wing panel 550 has been moved in direction1006 back to track 510, and is ready to be advanced (in a pulsed orcontinuous fashion) in a process direction 541 along track 510 tofurther work stations 520, shown as a rib-to-spar attach station 598,and a panel join station 599, at which a lower wing panel may be joinedto an upper wing panel to which ribs and spars have been attached. Thisoperation results in a wing assembly 600 awaiting installation of, forexample, further components, and/or electrical and other systems.

In FIG. 5F, rib-to-spar attach station 598 is shown to be disposed ontrack 510, whereas panel join station 599 is shown to be disposed offtrack 510, requiring movement of the wing panel 550 in direction 1008 tothe panel join station 599. This may represent a configuration in whichonly upper wing panels proceed along this portion of the assembly line500, with lower wing panels having been redirected to another track (notshown) or station, for example, by bypassing spar install station 530and rib-to-spar attach station 598, and instead being delivered to paneljoin station 599 to await joining to an upper wing panel. Or, a lowerwing panel may simply be transported through rib-to-spar attach station598 without any work operations performed on it, thus effectivelybypassing it. Or, in some embodiments, one or more work stations 520 maybe configured to have multiple purposes, for example to perform certainwork operations on, for example, upper wing panels, and other workoperations on lower wing panels. Such configurations are within thescope of this disclosure.

In accordance with the concepts, components, systems, and apparatusdiscussed above relative to FIGS. 5A-5F, it is evident that otherembodiments of an assembly line 500 that are consistent with thisdisclosure may take other configurations than those specificallyillustrated and described. For example, some embodiments may produce awing assembly using a different order of operations of joining wingpanels, ribs, and spars, and thus may include some or all of the variouswork stations 520 in a different order, or include work stations otherthan those shown, or multiples of work stations 520, or work stationsthat perform some or all of the functions of work stations 520 inaddition to other tasks, and so forth. In some of such embodiments,instead of spars and ribs being individually installed to a wing panel(such as an upper wing panel), as in the illustrated embodiments ofassembly line 500, spars and ribs may instead be attached to each other,to form a ladder-like structure (with the spars as the “rails” of theladder and the ribs forming the “rungs” thereof), which is theninstalled to a wing panel. Accordingly, such embodiments may include oneor more work stations that assemble spars to ribs (to which may besupplied ribs, spars or spar sections, and fasteners, from appropriatefeeder lines), and one or more work stations that install therib-and-spar structure to the wing panel, and/or install therib-and-spar structure between an upper wing panel and a lower wingpanel. As with the illustrated embodiment of assembly line 500, thevarious components and structures supplied to the aforementioned workstations may be configured for JIT delivery to the appropriate workstation.

An example of this is shown in FIG. 5G, which shows an alternativeconfiguration of an assembly line, indicated as assembly line 500′. FIG.5G generally corresponds with the top view of assembly line 500 shown inFIGS. 5C and 5E. However, whereas the assembly line configuration shownin FIGS. 5C and 5E includes a rib install station 528 and spar installstation 530, at which ribs 572 and spars 580, respectively, areindividually and separately installed to wing panel 550, the assemblyline 500′ shown in FIG. 5G instead is shown to include different workstations 520; specifically, a support structure assembly station 532,and a support structure install station 534. Support structure assemblystation 530 is supplied with ribs 572 and spars 580, and fasteningand/or sealing supplies, from one or more feeder lines 570 (arepresentative one of which is shown in FIG. 5G). For example, feederlines corresponding to 491-6 and 491-7, as shown in FIG. 4, may providespars and ribs, respectively, just in time and in the desired order tosupport structure assembly station 532 for assembly into a ladder-likesupport structure indicated at 588. Spars 580 may be preassembled orcomplete prior to provision to support structure assembly station 532,or may be provided thereto in the form of separate spar segments orsections (not individually shown) for assembly with ribs 572 intosupport structure 588.

When assembled, support structure 588 is transported (e.g., laterally)into support structure install station 534, as indicated by arrow 1014,and installed to wing panel 550. A cart or other manner of shuttle maytransport the support structure 588, which may then be raised upward tothe wing panel for installation. Alternatively or additionally, the wingpanel may be lowered to the support structure 588. Although not shown inthe view of FIG. 5G, fasteners and other supplies may be provided tosupport structure install station 534 together with the supportstructure, or separately via one or more feeder or supply lines. Assuch, FIG. 5G may show a state of assembly line 500′ just before acompletely assembled support structure 588 is delivered to supportstructure install station 534 for installation to a waiting wing panel550. The movement of wing panel 550, via strongback 540 along track 510,may be coordinated with the provision of an assembled support structure588, so that both the wing panel 550 and the support structure 588 aredelivered to support structure install station 534 at the same time, orone or the other may be provided just-in-time for installation, and soforth.

The wing panel 550, with a support structure 588 of ribs 572 and spars580 installed thereto, may proceed to a panel join station (such aspanel join station 599 shown in FIG. 5F) so that another wing panel,such as a lower wing panel, may be installed to the assembly. Thealternative configuration discussed above with respect to FIG. 5G mayoffer advantages over the configuration shown in assembly line 500, forexample by not involving transporting a wing panel laterally relative totrack 510 in order for spar installation to take place (as shown in FIG.5E), or by achieving efficiency in installing ribs and spars togetherrather than separately, and so forth.

With reference to the various components of and concepts and operationsembodied in, assembly line 500 presented in FIGS. 5A-5G and describedabove, FIG. 9 is a flowchart illustrating a method 860 of fabricating awing via an assembly line, such as assembly line 500, in an illustrativeembodiment. In step 862, a wing panel 550 is suspended beneath ashuttle, such as strongback 540, that enforces a contour 544 onto thewing panel 550. For example, in one embodiment the carriers 545 areaffixed to the wing panel 550 via vacuum couplers 548, and arevertically positioned to enforce the contour. As described above, insome embodiments, suspending the wing panel 550 includes indexing thestrongback 540 with the wing panel. The indexing may be a physicalcoupling (e.g., physically attaching to, or otherwise establishing alink with) between the strongback 540 and one or more indexing featuresinstalled in the wing panel 550, for example in a manufacturing excessof the wing panel 550. Additionally or alternatively, the indexingfeature may consist of or include readable identifying means, such as anRFID chip/tag or a bar code, and indexing includes reading theidentifying means with a suitable reader, such as an RFID reader, ascanner or bar code reader, and so forth (not shown).

In step 864, the wing panel 550 is advanced in a process direction, suchas process direction 541, through at least one work station 520 (andusually multiple work stations 520) in an assembly line 500 via thestrongback 540 while the contour 544 (e.g., as defined by upper surface574 of FIG. 5B) is enforced. For example, the strongback 540 may beadvanced along the track 510 while vacuum couplers 548 of the carriers545 to the wing panel 550 are disposed at vertical positions thatcorrespond with the contour 544. As noted above, enforcing a desiredcontour may be performed by aligning carriers 545 that each contact thewing panel at a predefined location on the wing panel, and during thisprocess, the wing panel 550 may advance through an NDI station such asNDI station 524, which performs NDI on the wing panel. During pausesbetween pulses, or during continuous motion, the wing panel 550 isindexed to the various work stations 520. This can be performed byindexing the work stations 520 to the indexing features 210 of the wingpanel 550 itself, such as described above with respect to indexing thestrongback 540 to the wing panel, or by indexing the work stations 520to indexing features of the strongbacks 540 carrying the wing panel 550.

In step 866, structural components such as ribs 572 and spars 580 areinstalled into the wing panel 550 while the contour 544 is enforced (bythe combination of strongback 540, carriers 545, and vacuum couplers).This may comprise co-bonding and/or fastening the ribs 572 and spars 580to the wing panel 550 while the wing panel 550 remains suspended fromthe strongback 540. Or, it may involve assembling ribs 572 and spars 580into a support structure 588, which is then installed to the wing panel550 while the wing panel remains suspended from the strongback. In oneembodiment, advancing the wing panel 550 comprises pulsing (e.g., byfull-pulse, or micro pulse) the wing panel in a process direction, andinstallation of ribs 572 and spars 580 is performed during pausesbetween the pulses. In a further embodiment, advancing the wing panel550 comprises continuously moving the wing panel in a process direction,and installation of ribs 572 and spars 580 is performed while the wingpanel continuously moves.

Although not specifically shown in FIG. 9, in some embodiments, method860 further includes additional operating work stations 520 arrangedalong the process direction to perform a variety of different workoperations, such as installing ribs and/or spars, joining ribs and/orspars to each other and/or to the wing panel, performing rework,inspecting the wing panel, cutting/installing access ports, and soforth. In some embodiments, multiple work stations 520 are provided toperform the same type of operation.

Method 860 may provide one or more technical benefits over priortechniques, for example because it enables a wing panel 550, or aportion thereof, to remain indexed to each of the work stations 520 in afabrication environment, even as the wing panel is transported throughmultiple work stations 520 for receiving work. That is, the wing panel550 remains indexed to the strongbacks 540 during transport, which meansthat the work stations 520 can rapidly index themselves to thestrongbacks 540, the wing panels 550, or both. Furthermore, thetechnique of suspending the wing panel 550 beneath a strongback 540enables greater and more ergonomic access and inspection of the wingpanel 550 during assembly processes (e.g., by technicians).

FIG. 10 is a flowchart depicting a method 880 of enforcing a contouronto a wing panel in an illustrative embodiment. According to method880, step 882 includes locating a wing panel for an aircraft beneath astrongback. As described in detail above, this step may involve moving awing panel 550 underneath a strongback 540 that is configured to extendover a transverse section of the wing panel, indexing the wing panel tothe strongback via indexing features (e.g., physical indexing featuresand/or readable identifying means) of the wing panel, hard stops, visualtechniques, and/or other processes. Step 884 includes engaging pogos ofthe strongback to an upper surface of the wing panel in positions thatare distinct from positions (e.g., corresponding positions on the lowersurface of the wing panel) that correspond to where structuralcomponents, such as ribs and spars, will be attached to the wing panel.As noted above, this is performed to allow fabrication access to the ribor spar install area, for example to facilitate manual or automateddrilling, fastener installation, and so forth, to allow ribs and sparsto be installed to wing panels. The ribs may be made from metallicmaterials or composites. If the rib is made from aluminum, then one ormore layers of fiberglass or other material are placed at anintersection between the aluminum and the carbon fiber. This can beaccomplished via fiberglass isolation plies along with sealant at thewing panel in areas where the ribs will be placed (sometimes referred toas the “rib land area”). In one embodiment, this comprises physicallyengaging the pogos to the upper surface, and activating vacuum systemsthat apply suction via the pogos to the wing panel.

Step 886 includes controlling a length of the pogos to enforce a contouron the wing panel while the wing panel is suspended beneath thestrongback. The pogos are independently adjustable. In one embodiment,controlling the length of the pogos is performed by setting the pogos toa predetermined length, while in further embodiments, this comprisesoperating actuators or air pressure to enforce specific lengths on eachpogo. When the pogos are all set to their desired lengths, the wingpanel is held in conformance with a desired contour at which ribs can beinstalled, provided the vacuum couplers of the respective pogos arelocated properly for the particular wing panel.

As noted above, in some embodiments, scanning is performed to determinean initial wing panel contour. It is possible that no changes in thecontour need to be enforced if the wing panel is already at a desiredcontour. In such circumstances, a retention force applied by each pogomay be less than in circumstances where a contour of the wing panel isactively enforced by the pogos. Adjustments to the length of each pogo(i.e., longer or shorter) relative to the strongback, e.g. to pushand/or pull the wing panel into a desired contour, is determined bydesign parameters for the wing panel. The locations of the vacuumcouplers of the pogos are precisely located relative to the uppersurface of the wing panel to ensure that when the pogos are at thedesired length, the contour enforced by the pogos corresponds withexpectations.

As noted above, in FIGS. 5A-5G, which show various aspects of assemblyline 500 (or 500′) for a wing assembly, including the operations thattake place as a wing panel 550 proceeds through a variety of workstations 520 disposed along the assembly line, many systems, operations,and components (e.g., ribs 572) are shown in simplified form and/orschematically, for ease of explanation. FIGS. 11A-11D illustrate, ingreater detail, the installation of additional components to wing panel550 in the production of a wing assembly 600. In particular, FIGS.11A-11D show the installation of a rib 572 to wing panel 550, which inthe embodiment shown is an upper wing panel 550-1, at rib installstation 528. As such, wing panel 550 may be referred to in the followingsection as “upper wing panel 550-1,” or simply as “wing panel 550-1,”for convenience. The term “wing assembly” refers to the structureproduced when wing components such as wing panels, ribs, and/or spars,are assembled together. As described in detail below, FIG. 11A shows arib 572 being moved into position beneath upper wing panel 550-1 bymeans of a shuttle, and FIGS. 11B and 11C show the rib being liftedupwards toward the lower surface of the upper wing panel forinstallation thereto. FIG. 11D shows a resulting wing assembly 600, withthe rib 572 installed to the wing panel 550-1, and with a pair of spars580 installed at either end of the rib 572.

The view shown in FIGS. 11A and 11B correspond generally with that ofview arrow “11” in FIG. 5C, and show wing panel 550-1, in a chordwisesectional view, suspended beneath a strongback 540 by means of pogos 545that are coupled with the upper surface 574 of the wing panel via vacuumcouplers 548, in accordance with the explanation provided above. Wingpanel 550-1, or at least the cross-sectional portion shown in FIG. 11A,is disposed within rib install station 528. As detailed in thediscussion above, the wing panel 550-1 may be indexed to the workstation 520, either directly or via one or more of the strongbacks 540supporting it. Wing panel 550-1 is shown to have several stringers 640installed to its lower surface 576, which are shown to have a T-shapedcross-section. While six stringers 640 are shown, a greater or fewernumber of stringers may be used for a particular upper wing panel and/orrib 572, and/or for a particular position along the spanwise length ofthe wing panel. In the context of an assembly line, such as assemblyline 500 shown in FIGS. 5A-5F (and/or assembly line 500′ shown in FIG.5G), stringers 640 may have been installed prior to rib installation,such as at any point upstream of the rib install station 528, orprovided during the initial fabrication of the upper wing panel from apreform.

Although a number of rib configurations are possible and within thescope of this disclosure, rib 572 in FIGS. 11A-11D is shown as anelongate, solid structure including a web 646 that is reinforced—thatis, held in contour—by a stiffener 648 (e.g., a beam or bracket thatenforces a contour onto the rib prior to affixing the rib to the wingpanel 550). The top and bottom edges of the rib 572 are shaped to followthe respective contours of the wing panels to which the rib 572 are tobe installed, and are provided with a number of openings or “mouseholes” 650 that are sized and positioned to accommodate, for example,stringers 640, as well as cables and other structure that may beinstalled (not shown). Web 646 also includes a number of access holes652 that are located inward from the edges of the rib, for similarpurposes.

In FIG. 11A, the rib 572 is advanced into position, and in oneembodiment enters the rib install station 528 from a feeder line(indicated at 570), which may be a rib feeder line (such as rib feederline 491-7), that supplies the ribs 572 to rib install station 528 in ajust-in-time or JIT timing scheme. More specifically, in FIG. 11A, therib 572 is held at a vertical orientation while being transported via ashuttle 700 (e.g., a manual cart or an automated cart propelled onrails, an Autonomous Guided Vehicle (AGV), etc.). The rib 572, asdiscussed above, may be fed via a just in time feeder line to theshuttle 700, and may be moved during a pause between pulses to enter therib install station 528. In the configuration shown, shuttle 700advances perpendicular to a process direction of the wing panel 550. Theshuttle 700 is shown to be driven by wheels 702 (e.g., motorized wheels)across floor 710, but may alternatively be disposed on rails, or atrack, and so forth. The wheels 702 drive the chassis 708, whichtranslates the chassis 708 horizontally/laterally in direction 1008, andthus transports the rib 572 to a position/location directly underneaththe wing panel 550. The shuttle 700 may include indexing features (notshown) to facilitate indexing of the cart relative to the rib installstation 528, to assure proper positioning of the shuttle relative to therib install station prior to advancing into position beneath the wingpanel 550, and/or of the shuttle (and thus the rib) relative to theupper wing panel 550-1 when the shuttle is advanced into position. Suchindexing features may take the form of cups and cones of a cup-and-coneindexing systems, hard stops, and/or other configurations. The chassis708 holds one or more actuators 704, as well as supports 706 that areaffixed to the actuators 704. Supports 706 are configured to cradle therib 572 in vertical orientation. The actuators 704 (or other liftingapparatus) are configured to drive the supports 706 vertically, such asto lift the rib 572 vertically into contact with lower surface 576 ofthe wing panel 550.

FIG. 11B shows the rib 572 after it has been driven vertically upward indirection 1010 to contact a lower surface 576 (e.g., onto a rib landarea) of the upper wing panel 550-1. The mouse holes 650 disposed alongthe upper edge of the rib 572 can now more clearly be seen to be sizedand positioned to accommodate stringers 640. The clearance between therib 572 and the stringers 640 at the mouse holes 650 may be greater orless than as shown. The rib 572 is held at a desired orientation andposition by supports 706, during the coupling to the wing panel.Although the disclosure has in the prior discussion used the term“installation,” this term may encompass a temporary or a permanentattachment. Thus, when the rib 572 is first brought into contact withthe wing panel, the coupling may be temporary, e.g., by clamping and/ortacking the rib 572 in place, or permanent, such as by the use oftemporary or permanent fasteners (e.g., via automated or manual drilland fastener installation techniques, before and/or after removal of theshuttle 700), or the rib 572 can be permanently affixed while alignedwith the upper wing panel 550-1. In some embodiments, for example thosedescribed further below with reference to FIGS. 16A-16C and FIGS.17A-17C, shims may be installed to fill gaps at the rib to wing panelinterface after the rib 572 has been temporarily fastened to the wingpanel, but prior to permanent installation thereto. Either way, oncecoupled to the upper wing panel 550-1, the coupling means hold the rib572 at the desired position, so the shuttle 700 may be removed.

In other embodiments, one or more strongbacks 540 suspend the upper wingpanel below via pogos 545 that form a vacuum attachment to the wingpanel, and lower the wing panel into contact with the rib 572 byadjusting lengths of the pogos (and/or lowering the strongback 540), asopposed to the rib 572 being raised upward to the wing panel. Stillother embodiments may employ a combination of movements of both rib 572,and upper wing panel, in order to bring the two components into contact.In some embodiments, the rib 572 is installed subsequent to theinstallation of a spar or spar segment (not shown in this view), and thespar facilitates holding of a contour (e.g., a spanwise contour, whilechordwise contour is held by the rib). Specifically, in such anembodiment, the spar 580 may prevent lateral (e.g. chordwise) shiftingof the rib 572, spanwise shifting of the ribs relative to each other,twisting of the ribs 572 and upper wing panel 550-1 about a spanwise 590axis, and so forth. Further, in some embodiments, a support structure(such as support structure 588) is assembled from ribs and spars, whichis then installed to the wing panel. Such embodiments may involve theuse of multiple shuttles, and/or a differently configured shuttle, ascompared to shuttle 700, to transport and/or lift the support structureto the wing panel.

FIG. 11C corresponds with view arrows 11C of FIG. 11B, and furtherillustrates the relationship between shuttle 700, rib 572, and upperwing panel 550-1. FIG. 11C further illustrates that in this embodiment,the upper wing panel 550-1, and specifically the lower surface 576thereof, includes an alignment feature 584 configured to align with acomplementary alignment feature 586 at the rib 572. The configuration ofalignment features 584 and 586 may be any that achieves registration ofthe rib with the upper wing panel 550-1, such as a cup-and-coneconfiguration, and so forth. There may be multiple corresponding pairsof indexing features for each rib. Furthermore, in some embodiments,alignment feature 584 is installed during fabrication of the upper wingpanel 550-1 as an indexing feature 210. These alignment featuresfacilitates alignment of the rib 572 prior to fastening the rib 572 tothe upper wing panel 550-1. Thus, in one embodiment, lifting the rib 572includes mating the rib 572 to an alignment feature 584 at the wingpanel 550. The ribs 572 are delivered as needed to the rib installstation 528 in a just in time (JIT) manner from a parallel assemblyline/feeder line. In this manner, different ribs are created in serialfor placement in wing assembly 600 in a pulsed environment as needed.

FIG. 11D is an end view of a wing assembly 600 that includes a wingpanel 550 (e.g., an upper wing panel 550-1) with attached ribs, of whichthe rib 572 is visible (i.e., rib 572 blocks the view of other ribsbehind it). The upper wing panel 550-1 is transported along an assemblyline in an illustrative embodiment; for example, via strongback 540,which conveys the upper wing panel 550-1 (now part of wing assembly 600)along track 510. Wing assembly 600 may be at least partially disposedwithin a rib install station 528, such as shown in the view presented inFIG. 5C. In the embodiment shown in FIG. 11D, however, spars 580 areshown to be installed to either side/on either end of rib 572; as such,the wing assembly 600 may be at least partially disposed within a sparinstall station 530, such as shown in the view presented in FIG. 5E, ora rib to spar attach station 598, such as shown in the view of FIG. 5F,depending, for example, on the order in which the spars 580 and ribs 572are installed.

In accordance with the components and operations discussed above, FIG.12 is a flowchart illustrating a method 900 of installing a rib into anupper wing panel in the production of a wing assembly in an illustrativeembodiment. The description of the method will refer to components andconcepts discussed above and shown in the drawings, but the method isapplicable to a variety of settings. Step 902 includes suspending anupper wing panel 550-1 of an aircraft beneath a shuttle, such asstrongback 540. In accordance with many of the methods described above,this step may include (and/or be preceded by) demolding the upper wingpanel 550-1 from a layup mandrel, indexing the upper wing panel to thestrongback 540, and/or coupling the wing panel with the strongback (suchas via vacuum couplers 548 of pogos 545) to hold the upper wing panelwhile enforcing a contour onto it.

Step 904 includes translating the rib to a position underneath the upperwing panel. This step may be performed while the wing panel is pausedbetween pulses through work stations. In some embodiments, this includesdriving a shuttle (such as cart 700, which may be a manually operatedcart, an AGV, or otherwise-configured vehicle) that supports the ribinto the desired position. The cart may be controlled according to an NCprogram, and may be positioned based on a track/rail system thatenforces a desired orientation, or marks at the factory floor thatindicate a desired position for placement, via radar or lidar, visualtracking, etc. In the illustrated embodiment, the position to which therib is translated is directly beneath the location on the upper wingpanel to which the rib will be installed.

Method 900 is shown to include a step 906 of orienting the rib 572vertically upright. In some embodiments, after demolding, the rib 572 isassembled or otherwise worked on while in an upright position, such ason a jig or similar frame, and thus may not need to be oriented uprightfor installation (for example if moved directly from the jig to the cart700 without changing its orientation). A jig may be used in order toplace or enforce a desired contour, such as a flat contour, onto therib. As noted above, a stiffener that runs the length of the rib iscoupled to the rib after demolding to enforce a contour onto the rib. Insome embodiments, the rib may be (or become) oriented in a directionother than a vertical orientation, such as during assembly or whilebeing supplied to the rib install station, such that vertically uprightorientation is needed prior to installation. In some embodiments, theorienting is performed by placing the rib 572 onto the cart 700, wherethe rib is then held at the desired vertical orientation by supports706. Method 900 may, in some embodiments, include supplying ribs in ajust in time (JIT) fashion, such as via a feeder line that is configuredto have a suitable takt time for JIT delivery.

Although in the illustrated embodiment, the “orienting” step 906 isshown to follow the “translating” step 904, this is not required to allembodiments. In some embodiments, the “orienting” step (906) isperformed as a part of, or at least partially during, the “translating”step (904). In some embodiments, orienting is performed prior totranslating (such as during loading the rib 572 onto the cart 700).

In step 908, the rib 572 is placed into contact with the upper wingpanel. As noted above, this may be performed lifting the rib vertically,such as by driving actuators 704 of the cart 700 to raise the rib 572into contact with the lower surface 576 of the upper wing panel 550-1.In some embodiments, this may be performed by lowering the upper wingpanel, such as by means of pogos 545 of the strongback 540, into contactwith the rib. In some embodiments, a combination of lifting the rib andlowering the wing panel is performed, in order to bring the componentsinto contact. In some embodiments, placing the rib 572 into contact withthe upper wing panel 550-1 includes mating the rib to one or moreindexing features of the wing panel (such as by coupling alignmentfeatures 584 and 586 as shown in FIG. 11C). This may ensure finalprecise alignment of the rib 572 with the upper wing panel 550-1.

As shown, for example, in FIG. 5D, the ribs 572 in some embodiments maybe fastened to the wing panel 550, or at least one or more portions ofthe lower surface thereof, at an angle, shown as installation angle θ.As such, in fabrication methods in which the rib 572 is orientedvertically, or in other words at an angle typically normal to a track510 and/or floor surface 710, and then lifted upward to the lowersurface of the wing panel, installing the ribs at the desiredinstallation angle θ relative to the wing panel may be facilitated bydisposing the wing panel in a suitable orientation, e.g., by disposingthe wing panel so that the lower surface thereof is canted at an anglethat is complementary to the installation angle θ. This may be doneduring initially suspending the upper wing panel 550-1 beneath thestrongback(s) in the suitable orientation, or the pogos may have theirlengths adjusted prior to the rib installation procedure in a mannerconfigured to change the orientation of the wing panel to one suitablefor installation of the ribs.

In step 910, the rib 572 is affixed to the upper wing panel 550-1 whilethe upper wing panel remains suspended from the strongback 540.Affixing, as the term is used herein, encompasses temporarily holdingthe rib in position, such as by tack fastening, clamping, and/or othertechniques, as well as permanently installing. In some embodiments, therib 572 is held in position prior to permanent installation, such as toallow selective installation of shims into gaps, if any, at the rib towing panel interface. In some embodiments, installing includes drivingor otherwise installing fasteners through the upper wing panel 550-1 andthe rib 572. These operations may be performed via end effectors thatinstall lockbolts, or by other means. In some embodiments, so as not toobstruct or interfere with fastening operations, vacuum attachmentperformed via vacuum couplers 548 located between or among, but in anycase, distinct from, rib install locations. Thus, in such embodiments,the vacuum couplers 548 are disposed on the wing panel 550 so that theirlocations do not interfere with operations such as tack fastening and/orpermanent fastener installation of the rib 572, performed by techniciansor automation.

Steps 904 (translating the rib), 908 (placing the rib into contact withthe wing panel), and 910 (affixing the rib to the wing panel) are allperformed while the wing panel 550 is suspended, and/or whilemaintaining the rib 572 vertically upright. One or more, or all, of thesteps of method 900 are performed at a rib install station. The method900, or a sequence of steps thereof, may be performed iteratively for aplurality of ribs 572 to be installed onto the same wing panel 550.

Method 900 provides a technical benefit over prior systems andtechniques, because it enables a contour to be enforced upon a wingpanel 550, and for ribs 572 to be rapidly installed into the wing panelwhile the contour remains enforced. By keeping the ribs verticallyoriented throughout the installation process, method 900 can save laborand increase efficiency on the factory floor and/or on an assembly line.

In some embodiments, after at least one rib has been affixed (e.g.,installed to upper wing panel 550-1), spars 580 are affixed to the ribsand to the wing panel, such as to close off the leading and trailingedge portions of the wing panels/ribs. In some of such embodiments,sections of spars are joined lengthwise to each other at a rib to make aspar, making the rib a part of the splice between spar segments. In someof such embodiments, spars 580 are affixed at a station downstream of arib install station, such as a spar install station, such as sparinstall station 530 of assembly line 500 as shown in FIGS. 5E and 5F. Inone embodiment, a spar 580 consists of three spar sections, so there aretwo spar/rib splices. In some embodiments, spars 580 and ribs 572 areaffixed simultaneously to a wing panel 550, such as at two differentstations and/or two different locations on the wing panel 550.

The installation of the ribs and spars to the wing panel, and to eachother, may include any suitable technique, including those disclosedherein. Some embodiments of the method 900 continue, such as with thejoining of a lower wing panel to the ribs and spars installed to theupper wing panel. A more detailed explanation of one manner in whichthis is carried out is provided below with reference to FIGS. 16A-16C,which illustrate one manner of installing shims during the assembly of awing assembly.

In some embodiments, there is a work station upstream of the sparinstall station where the wing panel is trimmed to final productiondimensions (e.g., its final perimeter) and the indexing features in themanufacturing excess are removed (i.e., along with the manufacturingexcess). This trimming is followed by sealing and painting, performed ina pulsed or continuous fashion. In some embodiments, trimming of thewing panel to its final perimeter (and/or sealing and painting) isperformed after ribs and/or spars are installed.

FIG. 13 is a flowchart illustrating a method 920 of assembling a wingassembly in an illustrative embodiment, which involves components,concepts, and processes discussed in detail above, but which focuses onthe aspect of the installation of ribs and spars to an upper wing panelwhile the wing panel is suspended beneath a shuttle. As such, step 922includes suspending an upper wing panel 550 of an aircraft beneath ashuttle, such as a strongback (for example, strongback 540). Step 924includes installing ribs 572 onto the upper wing panel 550-1. Step 926includes installing spars 580 onto the upper wing panel 550-1. Step 928includes fastening the spars 580 to the ribs 572. Finally, step 930includes joining a lower wing panel 550-2 to the spars 580 and ribs 572.

As noted above, the joining of the various wing assembly components mayoccur in a different sequence than as shown in the illustratedembodiments. In some embodiments, one or more of the ribs are installedprior to the installation of the spars (or spar sections). In someembodiments, all of the ribs are installed prior to the installation ofthe spars (or spar sections). In some embodiments, ribs and spars areinstalled at the same time, or overlapping in time, for example inmultiple work stations in an assembly line, and/or at multiple locationson the wing panel.

Further, in some embodiments, spars 580 (or spar sections) are joined toribs 572 prior to affixing the ribs to a wing panel (such as upper wingpanel 550-1), to produce a wing assembly having a horizontal, openladder-like structure such as support structure 588 (best seen in FIG.5G), to which the upper and lower wing panels 550 are then installed.FIG. 14 is a flowchart illustrating a further method 940 of assembling awing assembly in such an embodiment. The embodiment includes joining ofspars 580 to ribs 572 in step 942. An upper wing panel 550 is thenjoined to the spars 580 and ribs 572—or one side of the supportstructure 588—in step 944. This process may involve suspending the upperwing panel 550-1 beneath a shuttle, such as a strongback, as in otherexample methods, and raising the support structure 588 of joined ribsand spars into position to affix it to the upper wing panel. In some ofsuch embodiments, all of the ribs and spars are fastened together priorto joining with an upper wing panel; in others of such embodiments,further ribs and/or spars, or spar sections, are attached to the wingassembly after the support structure 588 is joined with the upper wingpanel. A lower wing panel is finally joined to the opposite side of thesupport structure 588 of the joined spars 580 and ribs 572 to completethe wing assembly, in step 946.

As noted above, in some configurations of an assembly line for a wingassembly, various work stations may be arranged in a manner thatfacilitates performing several operations on a wing panel at the sametime, or overlapping in time, as the wing panel is moved in a processdirection along the assembly line. FIG. 5A, for example, shows aconfiguration in which different sections of the same wing panel 550 arepositioned within multiple work stations 520; in particular, NDI station524, cut-out station 526, and rib install station 528. In otherembodiments, further work stations 520 such as spar install station 530(FIG. 5E), support structure assembly station 532 and/or install station534 (FIG. 5G), as well as a rib-to-spar attach station 598 and/or apanel join station 599 (see FIG. 5F) may also be so arranged.

FIG. 15 is a flowchart illustrating aspects of multiple operations beingperformed to a wing panel at the same time, or overlapping in time, andshows a method 960 of assembling a wing, or wing assembly, such as byinstalling a rib and spar to an upper wing panel, in an illustrativeembodiment. Step 962 includes suspending an upper wing panel 550-1 of anaircraft beneath a shuttle, such as a strongback (for example,strongback 540). Step 964 includes installing one or more ribs 572 andone or more spars 580 (or sections of spars 580) to the upper wing panel550 via stations 520 disposed at the upper wing panel, at the same timeor at least overlapping in time, while the upper wing panel remainssuspended. Step 966 includes pulsing the upper wing panel in a processdirection through the work stations 520. In some embodiments, additionalwork stations 520 also perform operations on the wing panel during theseoperations, including installing access ports (at a cut-out station),attaching ribs to spars (at a rib-to-spar attach station), and so forth.In a further embodiment, the work stations install ribs and spars duringpauses between pulses of the upper wing panel. In a further embodiment,the method further includes affixing a lower wing panel to rib(s) andspar(s) installed to the upper wing panel.

Various aspects of wing assembly, such as rib and spar installation to awing panel, may involve installation of shims between the wing panel andone or more ribs and/or spars, for example if any gaps between thevarious components exceed a certain size, such as a shimming tolerancethreshold. Shim installation may be performed, for example, after ribsand spars have been clamped and/or tacked into place, but before theribs and spars have been fastened together in the assembly line 500 ofFIG. 5A, before or after a lower wing panel has been attached. The shimsfill gaps between the various components (e.g., between a rib and theupper or lower wing panel, between a spar and the upper or lower wingpanel, between a rib and a spar, and so forth), once the components havebeen located to each other and tacked/clamped into place.

FIGS. 16A and 16B are diagrams illustrating automated installation ofshims between ribs and wing panels in illustrative embodiments,specifically by means of an end effector of a robot arm that may bedetachably coupled to the stiffener of each rib. In more detail, asshown in both FIGS. 16A and 16B, a wing assembly 600 is suspended belowa strongback (not shown) by means of adjustable-length pogos 545 thatinclude vacuum couplers 548 that are coupled to the upper surface 574 ofa wing panel 550 of the wing assembly. FIG. 16A shows an embodiment inwhich the wing assembly 600 includes one wing panel 550, in the form ofan upper wing panel (indicated at 550-1), whereas FIG. 16B shows anembodiment in which the wing assembly 600 also includes a second wingpanel 550 in the form of a lower wing panel (indicated at 550-2). Thewing assembly 600 is shown to have a number of ribs 572 affixed to thelower surface 576 of the upper wing panel 550-1.

In some embodiments, there may be one or more gaps between coupledcomponents of a wing assembly 600, such as between a rib 572 and thesurface of the wing panel to which it is installed, between a spar 580and a wing panel 550, between a rib 572 and a spar 580, and so forth. Ifa gap is determined to exceed a certain size, in that one or moredimensions of the gap (e.g., width, depth, length, etc.) exceeds acertain threshold, which is also referred to herein as a shimmingtolerance threshold, then a shim of a suitable size and configuration isinstalled into the gap, to fill it. In the illustrated embodiment, thisis done by a robot arm 750, and more specifically by an end effector 752of the robot arm. End effector 752 is shown in FIG. 16A to include agrasping device 754 configured to hold a shim 756, such as to installinto a gap that has been determined to be a shim location (indicated as758). In some embodiments, the end effector 752 includes components ordevices for inspection (not shown), such as a camera, laser, ultrasonicdevice, probe or feeler gauge, and so forth, in order to scan orotherwise visually or physically detect or assess gaps along the jointbetween joined components, and further to make or enable thedetermination of whether a gap exceeds a shimming tolerance thresholdand is thus a suitable location for installation of a shim 756 (i.e. ashim location 758). In some embodiments, the robot arm 750 includesmultiple end effectors 752, such as one for inspection and another forinstallation.

Although other configurations are possible, in FIG. 16A, robot arm 750is shown as a kinematic chain of actuators 760 and rigid bodies 762 thatextends from a carriage 764. Carriage 764 is in turn mounted onstiffener 648 of the rib 572. Stiffener 648 is also referred to hereinas a “bracket.” In some embodiments, such as described above, thebracket 648 is installed to the rib 572 prior to installation of the ribto the wing panel 550, to function as a stiffener, that is, to stabilizethe rib and/or enforce a desired (e.g. flat) contour to the rib. Assuch, bracket 648 in some embodiments serves both as a stiffener and asa connection point for the robot arm. In further embodiments, thebracket 648 may additionally or alternatively serve as a generalconnection point for machinery or equipment used to move or otherwisehandle the rib during fabrication and/or assembly operations. In someembodiments, the bracket is removably attached, e.g. with bolts or otherlike fasteners. As detailed further below, the coupling between thecarriage 764 of the robot arm 750 and the bracket 648 of the rib 572 isa removable one, so that the robot arm may be coupled and de-coupledfrom the bracket via a detachably mounting the carriage 764 on thebracket. Further, in the illustrated embodiment, the coupling is suchthat the carriage 764 is independently movable along the length of thebracket, such as to facilitate the robot arm to access gaps and/or shimlocations 758 along the length of the rib 572.

The robot arm 750 may be moved (e.g. relocated) from one bracket toanother, such as by being decoupled from a first bracket and thencoupled to a second one, to operate in different locations along thewing assembly 600. In the embodiment shown in FIG. 16A, this is done bymeans a cart 770. Cart 770 includes a set of wheels 772 mounted to andconfigured to support a cart body 774 relative to a surface, such as afloor surface. One or more wheels 772 may be motorized or otherwisedriven. Cart body 774 in turn supports a telescopic lift 776, which isconfigured to engage, and raise or lower, carriage 764. As such, cart770 is configured to position the carriage 764 for coupling to bracket648, or to move the carriage after it is de-coupled from the bracket ofa first rib 572 to a position in which it may be coupled to a bracket ofa second rib, and so forth, such as by a combination of raising orlowering the lift 776 and moving the position of the cart body relativeto a floor surface (and/or rib 572) by means of wheels 772.

As depicted, cart 770 also includes a controller 778, which maypartially or completely control the movements of cart body 774 and/orlift 776, and/or the coupling/decoupling of carriage 764 relative to abracket of a rib 572. Controller 778 may, in whole or in part, controlthe operations of robot arm 750 and its end effector 752. In someembodiments, robot arm 750 is operated in accordance with an NC programby controller 778 to visually inspect a location between the rib 572 andthe wing panel 550, in order to determine whether shims 756 will beused, and what size of shims will be used, and/or to install the shims.In other embodiments, some or all of these movements are remotelycontrolled, such as by an operator, or by a floor controller (notshown). Thus, it can be understood that FIG. 16A illustrates multipleoperations. For example, cart 770 and lift 776 are shown to cooperate toposition carriage 764 in contact with bracket 648 of a rib 572. Also,robot arm 750, which extends from carriage 764, is shown to have its endeffector 752 holding a shim 756 for installation into shim location 758.The various components of the cart 770 and robot arm 750 are shown insimplified, partially schematic form, for ease of explanation. Cablingand wiring, such as to provide power to the robot arm 750 and/or cart770 from an external or integrated power source (not shown), and soforth, are not illustrated in this view.

FIG. 16A also shows a shim feeder line schematically represented at 780,which, in the illustrated embodiment, is configured to supply shims 756for installation by robot arm 750. In some embodiments, shim feeder line780 is configured to dynamically fabricate shims 756 for installation,such as responsive to signals or communications provided by an operatorand/or controller 778, based on input received from an end effector 752configured to measure or otherwise assess each gap that is encounteredduring an analysis.

As such, it can be seen that an example operation of automatic shiminstallation for a wing assembly may proceed by assessing each of asequence of locations in a wing assembly, such as each of a series oflocations in which, for example, prior analysis indicates that a shimlocation 758 exists (or may exist), or the entirety of each of thejoints between components that are joined together, and so forth. In oneexample, the carriage 764 of the robot arm 750 is sequentially coupledwith the bracket 648 of each of several ribs 572 installed to a wingpanel 550, to perform detection and analysis of each gap, and/or shiminstallation for each shim location 758, in the space bounded by one ortwo adjacent ribs 572. This space is also referred to as a bay 790. Asnoted above, in such an example, the carriage 764 may move along thebracket 648 to allow inspection and/or installation of the entire lengthof the rib 572, or at least the sides of the ribs (or rib) that definethe bay in which the robot arm 750 is mounted. In the embodiment shownin FIG. 16A, five ribs 572 (also individually indicated as 572-1, 572-2,572-3, 572-4, and 572-5), are shown installed to upper wing panel 550-1,forming six bays 790 (which are only individually indicated, as 790-1,790-2, 790-3, 790-4, 790-5, and 790-6). Carriage 764 is shown coupled tothe bracket 648 of rib 572-4, allowing end effector 752 of robot arm 750to inspect and/or install shims 756 not only to the side of rib 572-4 towhich the bracket 648 is installed, but also to one side of the nextadjacent rib (that is, rib 572-3), and any other location accessible inbay 790-4. Accordingly, by coupling the carriage 764 of the robot arm750 to the bracket 648 of each rib 572, shim installation may beperformed in each bay 790-1, 790-2, etc. In a bay in which there is nota bracket 648 to which carriage 764 may be coupled, such as bay 790-6 inFIG. 16A, gap inspection and/or shim installation may be performed bymoving the robot arm 750 by means of the cart body 774 and telescopiclift 776. In other embodiments, additional brackets may be installed inorder to allow inspection and/or shim installation solely by means of abracket-mounted robot arm 750. There may be more or fewer ribs (andcorrespondingly more or fewer bays) in different wing assemblies. Insome embodiments, the robot arm 750 is coupled with a bracket 648 of arib 572 prior to the rib being placed against the wing panel.

In some cases, a shim location 758 may be detected and/or assessed fromboth sides of a rib 572, in which case shim installation may beperformed from whichever side enables a more efficient operation. Insome embodiments, multiple robot arms are simultaneously deployed on thesame wing assembly, which (among other benefits) may facilitateefficient shim installation in shim locations that may be fillable fromeither side. In some of such embodiments, a single cart may facilitatethe positioning (and re-positioning) of each of multiple robot arms,such as by lifting a carriage of a first robot arm into place formounting on a first bracket, then disengaging from the carriage to leavethe robot arm on the first bracket, then moving to engage a carriage ofa second robot arm, such as to move it into place for mounting on asecond bracket (e.g., in a different bay), and so forth.

In FIG. 16B, as noted above, wing assembly 600 is shown to also includelower wing panel 550-2. Also, the telescopic lift 776 is shown to extendthrough an access port 792 in the lower wing panel 550-2 in order toaccess the bracket 648, such as to couple (or de-couple) carriage 764 to(or from) the bracket. Access port 792 may have been installed at anupstream work station 520, such as cut-out station 526 as shown in FIG.5A. Access port 792 is sized to allow insertion and subsequent removalof robot arm 750 (including carriage 764). To minimize the size ofaccess port 792, robot arm 750 may be extended, or folded, or otherwisealigned into a configuration having a minimal cross-section forinsertion and withdrawal through the access port. Alternatively, robotarm 750 may be sized and/or configured specifically to fit through apredetermined access port size. Lower wing panel 550-2 is shown toinclude several access ports 792, one for each bay, to allow a robot arm750 to be inserted and then coupled in order to perform inspectionand/or shim installation in each bay. In one embodiment, the sides ofthe two ribs that define a bay are inspected and/or shimmed by the robotarm 750 while it is disposed within that bay, which reduces the numberof times that the robot arm 750 is aligned with the access port 792 forinsertion or removal.

In some embodiments, FIGS. 16A and 16B depict two phases of a sequentialoperation, in which installation of shims 756 (e.g., upper shims) toshim locations 758 between ribs 572 and the lower surface of the upperwing panel 550-1 is first performed (as shown in FIG. 16A), followed byinstallation of the lower wing panel 550-2 to the wing assembly 600,followed by installation of shims (e.g. lower shims) to shim locationsbetween ribs 572 and the upper surface 574 of the lower wing panel 550-2(as shown in FIG. 16B). In other words, in such embodiments, the lowerwing panel 550-2 is installed after the upper shims are installed. Inother embodiments, FIGS. 16A and 16B depict alternative operations—forexample, FIG. 16A may represent the first stage of the sequentialoperation described above, whereas FIG. 16B may represent an operationin which lower wing panel 550-2 is installed to the wing assembly 600before installation of any (upper or lower) shims 756. In either case,the robot arm 750 may be moved from bay to bay along the length of thewing assembly by means of the cart 770 in order to perform shiminstallation in each bay. As described above, in some embodiments,multiple robot arms are deployed for shim location detection and/oranalysis, and/or shim installation, in more than one bay, at the sametime.

FIG. 16C depicts a view of a rib 572 to which the carriage 764 of robotarm 750 is installed—specifically, rib 572-4 as shown in FIG. 16A—andthus corresponds with view arrows 16C of FIG. 16A. However, thecomponents illustrated in FIG. 16C are applicable to any rib 572 in theillustrated embodiment. Only carriage 764 of the robot arm is shown inFIG. 16C, for clarity, and components of the strongback (e.g. pogos andvacuum couplers) are also not shown in this view. FIG. 16C provides aview of an illustrative example configuration of bracket or stiffener648, which is shown to be installed against the web 646 of the rib 572.More specifically, the bracket 648 is shown to be mated with indexingfeatures at the rib 572, which are generically shown as indexingfeatures 794. The indexing features may facilitate alignment of thebracket 648 with the rib 572 during installation thereto, and may takeany suitable form, such as through-holes in web 646 that are configuredto receive fasteners such as bolts. FIG. 16C further illustrates thatthe bracket 648 comprises a rack 796 having teeth 798 to which thecarriage 764 is clamped or otherwise removably attached. The carriage764 is configured to utilize the teeth 798 to translate back and forthalong the bracket 648 in a controllable and indexed manner (e.g., via adriven mechanism that engages the teeth, such as a pinion, a worm gear,and so forth). The position of the robot arm may thus be indexed withrespect to a rib, such as the rib to which the carriage of the robot armis coupled, based on a position of the bracket 648 (or relative to thebracket 648), and a position of the carriage 764 along the bracket 648.Although not required to all embodiments, bracket 648 in FIG. 16C isalso shown to include a centering feature 654 that may facilitateindexing, such as by enabling more rapid determination the position ofthe carriage to a known reference point.

In one embodiment, the carriage 764 is operable to drive the robot arm(not shown) along the bracket 648 via a rack-and-pinion system in whichthe teeth 798 form the rack. Other embodiments of bracket 648 and/orcarriage 764 have a different configuration to enable movement ofcarriage 764 along the bracket. In the illustrated embodiment, thecarriage 764 is also capable of rotation, as shown by arrow 1012, inorder to enhance movement of, and access by, the robot arm.

FIG. 16C also shows a representative pair of spars 580 installed to theupper wing panel 550-1, at either end of the rib 572. The spars 580 areillustrated in a simplified form and thus are not shown to include, forexample, specialized upper and lower cap shapes that facilitate fastenerconnections to a wing panel. Teeth 798 are shown to extend sufficientlytoward the ends of the bracket 648, which in this embodiment iscoterminous with the rib 572 to which it is installed, to allow thecarriage 764 to move close enough to the spars so that gap assessmentand/or shim installation by the robot arm may be performed at thejoint(s) between the spar and the wing panel(s), and/or at the jointbetween the spar and the rib. In further embodiments, the bracket 648facilitates track mounting of a collar and/or nut installer. This may beparticularly beneficial in circumstances where a lower wing panel isalready installed and access is only available through access ports.Also, although the rib 572 and wing panel 550 are not shown to accuratescale or dimension, FIG. 16C shows that a number of gaps exist betweenthe rib 572 and the lower surface 576 of the upper wing panel 550-1,such as at representative shim location 758.

As noted above, in some embodiments, the robot arm 750 performsoperations in addition to shim installation, such as detection and/orinspection of gaps to facilitate the identification of shim locations758. In some embodiments, the robot arm performs additional operationsincluding sealing, sealant inspection, fastener installation, collar ornut installation on fasteners, collar or nut installation inspection,and so forth. The robot arm 750 may perform such operations via aselection of interchangeable end effectors 752 (which, for example, maybe exchanged while the carriage 764 of the robot arm 750 is coupled tothe bracket 648, such as via an access port 792), or performed withmulti-functional end effectors 752, or with multiple robot arms 750 thatcan each be installed and left in place on a bracket, in some cases withmore than one such robot arm coupled to a bracket. The robot arm 750 maybe operated automatically or remotely via a floor-based controller thatenables a technician to operate the robot arm (e.g., via remotecontrol). After completing its work, a robot arm 750 can be re-attachedto the cart 770 and removed.

FIGS. 17A-17C are perspective views of robot arms 750 each operating toinspect gaps, install shims 756 in shim locations 758, install sealantor collars/nuts, and so forth, in a bay 790 disposed between two ribs572 and bounded on one side by a spar 580 of an example wing assembly600. In the embodiments depicted in these drawings, a technician setsup, operates, and maintains the robot arm 750, after placement of thecarriage 764 of the robot arm on a bracket 648 via a cart (not shown).For simplicity, the following discussion assumes that the robot arm 750operates in the same bay 790, between the same two ribs 572(individually numbered as 572-1 and 572-2), in each of this series ofdrawings. In FIG. 17A, the robot arm 750 is mounted on a bracket 648installed against rib 572-1, and operates its end effector 752 toinspect ribs 572 placed against an upper wing panel 550, andspecifically a location between rib 572-2 and the surface of the wingpanel 550 against which it is positioned. Based on the inspection, therobot arm 750 will selectively install shims 756 at shim locations 758within the bay. In FIG. 17B, the carriage 764 of the robot arm 750 hasprogressed along the bracket 648 to a position closer to the end of thebracket as compared to its position in FIG. 17A, and is shown using itsend effector 752 to inspect a location near the bottom of rib 572-2. InFIG. 17C, the robot arm 750 has used its end effector 752 to place ashim (not shown) at a shim location 758 above bracket 648, where rib572-1 is affixed to upper wing panel 550. With the shim in place,fasteners may be installed through the upper wing panel 550 and the rib572-1 to secure the wing panel to the rib, or at least the portionsthereof that are local to the shim, with the shim in place. In someembodiments, a shim is fastened in place by means of one or morefasteners; in some embodiments, a shim is instead held in place in afriction fit due to the fastening of the rib to the wing panel.

With the aforementioned components and concepts in mind, FIG. 18 is aflowchart illustrating a method 920 for operating a robot arm (such asrobot arm 750) to perform tasks related to wing assembly (such as in awing assembly 600) in an illustrative embodiment. Step 922 includesmounting a bracket 648 to a rib 572. In some embodiments, this is doneprior to holding or placing the rib against a wing panel 550, such asafter demolding the rib and during (or after) other preparation of therib for installation to the wing panel. In some embodiments, this isdone after holding or placing the rib against the wing panel. Mountingthe bracket 648 may be facilitated by aligning the bracket with indexingfeatures of the rib 572 (e.g., complementary cup-and-cone features,through-holes for receiving bolts, and so forth). Once mounted, thebracket 648 enforces a desired contour, such as a flat contour, onto therib 572. In some embodiments, the bracket is removably mounted.

After the bracket 648 has been mounted to the rib 572, step 924 includescoupling a robot arm 750 to the bracket. In some embodiments, this isperformed by detachably mounting a carriage 764 on the bracket. In someof such embodiments, a wheeled cart 770 that is outfitted with atelescopic lift 776 configured to support the carriage is deployed, forexample for moving the carriage into a suitable orientation and/orposition for mounting on the bracket. The coupling of the robot arm 750to the bracket 648 may be accomplished via clamping, suction, magnets,mechanical alignment with a track on the bracket, and so forth. In someembodiments, the coupling is configured to allow the robot arm 750 tomove relative to the bracket 648, such as by means of a carriage 764configured for movement along the bracket. In some of such embodiments,the bracket includes teeth that facilitate a rack and pinion system withthe carriage. With the carriage 764 and/or the robot arm 750 coupled tothe bracket 648, a location of the robot arm 750 within the referencesystem of the wing assembly 600 (e.g., relative to one or morecomponents of the wing assembly, such as a wing panel, or a rib, or abracket mounted to the rib, or a spar, and so forth) is known. In thatsense, coupling the robot arm 750 to the bracket 648 may includeindexing the position of the robot arm relative to the bracket.

Once coupled, in step 926, the robot arm 750 is operated to install oneor more shims between the rib and the wing panel, at the rib to wingpanel interface (i.e. while the robot arm is coupled to the bracket 648,via the carriage 764). As explained above, this may include moving therobot arm 750 (e.g., by driving the carriage 764) along a length of thebracket 648, in order to align the robot arm 750 with shim locations atthe rib, and/or move the robot arm within range of additional shimlocations.

In some embodiments of the method 920, the robot arm is operated, via asuitably configured end effector, to inspect the rib to wing panelinterface, such as to detect, inspect, and/or measure gaps between thecomponents. In some of such embodiments, the result of a measurement iscommunicated, e.g. to a technician or a controller, to determine whethera particular gap exceeds a shimming tolerance threshold, which mayrepresent an out of tolerance condition, and thus is considered to be ashim location (into which a shim is installed). In some of suchembodiments, the result of a measurement is used to select a suitableshim to be installed, e.g., by size, dimension, taper, or othercharacteristic, to rectify the out of tolerance condition.

Shims 756 may be supplied via a shim feeder line in any suitable manner.For example, a selection of shims (e.g. of differing tapers and/orsizes, etc.) may be stocked in a bin accessible to the robot arm. Insome embodiments, a new shim is dynamically fabricated, or apre-fabricated shim is adjusted (e.g., trimmed), such as based oninspection and/or measurement of the gap, and then delivered forinsertion into the shim location 758 and provided just in time forplacement.

After the shim 756 has been installed, the method may further includeretracting the robot arm 750, and moving the carriage 764 to a newlocation along the bracket 648 for further shim installation and/orother operations. If shim 756 installation into shim locations 758accessible from the bracket 648 is complete, then the carriage 764 maybe decoupled from the bracket, and moved to a new location (such as tothe bracket of another rib). In some embodiments, this is facilitatedwith a wheeled cart outfitted with a telescopic lift. In someembodiments, this involves removing the robot arm 750 through an accessgap, such as in a lower wing panel 550-2.

As can be appreciated with respect to the description above of FIGS. 16Athrough 17C, method 900 may be employed in a wing assembly 600 thatincludes a variety of components and configurations. For example,although described in the context of an embodiment in which one rib isheld against a wing panel, the method may be employed iteratively in awing assembly that includes multiple ribs held against the wing panel.In other words, once steps 922, 924, and 926 are performed to installshims in shim locations between a first rib and a wing panel, the stepsmay be repeated to install shims to shim locations between a second riband the wing panel. Method 900 may further be employed in a wingassembly 600 in which multiple ribs 572 are held at their upper edgesagainst a wing panel, such as an upper wing panel 550-1, and in whichanother wing panel, such as a lower wing panel 550-2, is held againstthe opposite (or lower) edges of the ribs. In such a configuration, thelower wing panel 550-2 may be added to the wing assembly prior to, orbetween, shim installation operations. In one example, the methodincludes performing steps 922, 924, and 926 first for upper shimlocations between the ribs and the upper wing panel, followed by theaddition of the lower wing panel to the wing assembly, followed byperforming steps 922, 924, and 926 for lower shim locations between theribs and the lower wing panel. As noted above, subsequent to shiminstallation between a rib and a wing panel, the rib may be fastened(e.g. installed) to the wing panel. In another example, the methodincludes performing shim installation on both upper and lower shimlocations, for example in a configuration in which the lower wing panelhas already been placed. In either of these examples, the methodincludes repositioning the robot arm, for example to couple the carriageto the brackets of different ribs, by moving (e.g. withdrawing andinserting) the robot arm through access gaps in a wing panel, such as inthe lower wing panel.

Turning now to FIG. 19, an illustration of a representative aircraft1200 is depicted in which an illustrative embodiment of a wing paneland/or a wing assembly produced in accordance with aspects of thepresent disclosure may be implemented. In other words, aircraft 1200 isan example of an aircraft which can be formed using composite parts,wing panels, and/or wing assemblies produced according to one or moreaspects of: the illustrative fabrication methods shown in FIG. 1 andFIGS. 2A and 2B; the illustrative schema shown in FIG. 4; theillustrative assembly line 500 shown in FIGS. 5A-5F; the illustrativerib and spar installation techniques shown in 11A-11D; the illustrativeshim installation techniques shown in FIGS. 16A-16C and FIGS. 17A-17C;one or more of the methods shown in the remaining drawings; and/or anyof the aforementioned as discussed above. In this illustrative example,aircraft 1200 has wings 1202 attached to and extending to either side ofa fuselage 1204. Aircraft 1200 includes an engine 1206 attached to eachwing 1202. Disposed at the rear end of fuselage 1204 is tail section1208, which includes an opposed pair of horizontal stabilizers 1210 anda vertical stabilizer 1212. Wings 1202 are formed of an upper wing panel550 and a lower wing panel (not shown) joined together, with an assemblyof ribs and spars (not shown) at least partially forming the interiorstructure thereof.

FIG. 20 is a block diagram of various components and systems (or stages)discussed herein in an illustrative embodiment. Specifically, FIG. 20depicts a factory 1300 that includes a first assembly line 1310 in aclean room environment indicated at 1312, and a second assembly line1314 in a non-clean room environment 1316. A boundary (e.g., one or morewalls or enclosures), represented at 1318, separate the clean room 1312and non-clean room 1316 environments. At layup 1320, indexing features(such as indexing features 210) are integrated into a laminate 1322(such as preform 200) for a wing panel. The laminate 1322 is hardened atan autoclave 1324 into a composite part 1326. In accordance with theembodiments herein, the composite part 1326 is a wing panel (e.g., wingpanel 550), and more specifically an upper wing panel, but factory 1300may be configured to fabricate, process, and otherwise do work uponcomposite parts that take the form of other aircraft components inaddition to a wing panel. The composite part 1326 is then transitionedto the assembly line 1314, which in the illustrated embodiment is shownto progress the composite part 1326 in a process direction 1328 throughvarious systems and stages specific to those appropriate for an upperwing panel. For example, at the assembly line 1314, a trimming stage1330 removes excess material and/or installs additional indexingfeatures into the composite part 1326. At demolding 1332, the compositepart 1326 is demolded (e.g., removed from a layup mandrel), after whicha contour is enforced onto the composite part 1326 via contourenforcement 1334, in which the composite part 1326 is affixed to ashuttle 1336 (such as one or more strongbacks 540) that includescarriers 1338 (e.g., adjustable-length pogos 545 that include vacuumcouplers 548). The shuttle 1336, such as via the carriers 1338, enforcea contour onto the composite part 1326 as the composite part is advancedalong the assembly line 1314. Ribs and spars are installed onto thecomposite part 1326 as it is progressed through rib installation 1340and spar installation 1342. Inspection of the rib and spar assembly, andshim installation, is performed by a robot arm 1344, as needed. A lowerwing panel 1346 is then attached to form a wing assembly (e.g., wingassembly 600). The various systems and stages described with regard tofactory 1300 may incorporate or be in the form of the various workstations 520 discussed above. Moreover, not all of the work stations 520described above are specifically shown in FIG. 20, for simplicity,although the assembly line 1314 may include such stations as one or moreNDI stations 524, cut out stations 526, and so forth. Other operationsdescribed above with respect to FIG. 20 may incorporate or be in theform of one or more of the feeder, layup, or assembly lines shown inschema 480 and shown in FIG. 4; for example, trimming 1330 and demolding1332 may take place in a demolding operation 490-11.

Attention is now directed to FIG. 21, which broadly illustrates controlcomponents of a production system that performs (e.g. continuously)lamination and/or ultrasonic inspection in an illustrative embodiment. Acontroller 1400 coordinates and controls operation of laminators 1420and movement of one or more mobile platforms 1470 along a moving line1460 having a powertrain 1462. The controller 1400 may comprise aprocessor 1410 which is coupled with a memory 1412 that stores programs1414. In one example, the mobile platforms 1470 are driven along amoving line 1460 that is driven continuously by the powertrain 1462,which is controlled by the controller 1400. In this example, the mobileplatform 1470 includes utility connections 1472 which may includeelectrical, pneumatic and/or hydraulic quick disconnects that couple themobile platform 1470 with externally sourced utilities 1440. In otherexamples, as previously mentioned, the mobile platforms 2470 maycomprise, e.g., mandrels and/or other tools, parts, supplies, and soforth, on automated conveyances such as Automated Guided Vehicles (AGVs)that include on board utilities, as well as a GPS/autoguidance system1474. In still further examples, the movement of the mobile platforms1470 is controlled using laser trackers 1450. Position and/or motionsensors 1430 coupled with the controller 1400 are used to determine theposition of the mobile platforms 1470 as well as the powertrain 1462.

FIG. 22 depicts a view of an assembly line 1500 in an illustrativeembodiment (e.g., of a continuous assembly line), in terms of aprogression of work zones 1502 arranged along a moving line andconfigured to perform a variety of operations. The work zones include awork zone for tool preparation 1510 involving cleaning of, orapplication of coatings and/or potting compound to, or repairs to, atool 1504 (e.g., layup mandrel 110), following which the tool 1504 istransported on a platform 1506 to additional work zones 1502. Theadditional work zones include a work zone for material application 1520(e.g., where lamination operations are performed) in order to form apreform 1522 (such as preform 200). The preform 1522 may then bedelivered via the assembly line 1500 to downstream work zones, includinga work zone for debulking 1530 and, a work zone for compaction 1540, anda work zone for molding 1550. Debulking and/or compacting the preform1522 may comprise vacuum compaction performed via a vacuum bag 1532.Molding the preform 1522 may be performed via precure forming, and/orvia a combination of molding between the tool 1504 and a caul plate1542.

The preform 1522 is further moved to work zone for hardening 1560 thepreform 1522 into a composite part 1564 (e.g., composite part 250, whichmay be in the form of a wing panel 550), such as at an autoclave 1562, awork zone for trimming 1570 (e.g., via cutters 1572) the composite part1564, a work zone for inspection 1580 (e.g., via an NDI machine 1582) ofthe composite part 1564, a work zone for rework 1590, and/or a work zonefor surface treatment 1595.

In one embodiment, the trimming process may involve mass trimming of thepreform 1522 before it is hardened, followed by more specific trimmingafter the composite part 1564 has been formed. Inspection of thecomposite part 1564 may include visual inspection as well as inspectionusing NDI (nondestructive inspection) equipment. Although reworking thecomposite part 1564 along the assembly line 500 is possible, in manycases the composite part 1564 may not require rework. The composite part1564 then proceeds in process direction 541 through assembly line 500.

EXAMPLES

In the following examples, additional processes, systems, and methodsare described in the context of a fabrication and assembly system forwings for aircraft.

Referring more particularly to the drawings, embodiments of thedisclosure may be described in the context of aircraft manufacturing andservice in method 1600 as shown in FIG. 23 and an aircraft 1602 as shownin FIG. 24. During pre-production, method 1600 may include specificationand design 1604 of the aircraft 1602 and material procurement 1606.During production, component and subassembly manufacturing 1608 andsystem integration 1610 of the aircraft 1602 takes place. Thereafter,the aircraft 1602 may go through certification and delivery 1612 inorder to be placed in service 1614. While in service by a customer, theaircraft 1602 is scheduled for routine work in maintenance and service1616 (which may also include modification, reconfiguration,refurbishment, and so on). Apparatus and methods embodied herein may beemployed during any one or more suitable stages of the production andservice described in method 1600 (e.g., specification and design 1604,material procurement 1606, component and subassembly manufacturing 1608,system integration 1610, certification and delivery 1612, service 1614,maintenance and service 1616) and/or any suitable component of aircraft1602 (e.g., airframe 1618, systems 1620, interior 1622, propulsionsystem 1624, electrical system 1626, hydraulic system 1628,environmental 1630).

Each of the processes of method 1600 may be performed or carried out bya system integrator, a third party, and/or an operator (e.g., acustomer). For the purposes of this description, a system integrator mayinclude without limitation any number of aircraft manufacturers andmajor-system subcontractors; a third party may include withoutlimitation any number of vendors, subcontractors, and suppliers; and anoperator may be an airline, leasing company, military entity, serviceorganization, and so on.

As shown in FIG. 24, the aircraft 1602 produced by method 1600 mayinclude an airframe 1618 with a plurality of systems 1620 and aninterior 1622. Examples of systems 1620 include one or more of apropulsion system 1624, an electrical system 1626, a hydraulic system1628, and an environmental system 1630. Any number of other systems maybe included. Although an aerospace example is shown, the principles ofthe invention may be applied to other industries, such as the automotiveindustry.

As already mentioned above, apparatus and methods embodied herein may beemployed during any one or more of the stages of the production andservice described in method 1600. For example, components orsubassemblies corresponding to component and subassembly manufacturing1608 may be fabricated or manufactured in a manner similar to componentsor subassemblies produced while the aircraft 1602 is in service. Also,one or more apparatus embodiments, method embodiments, or a combinationthereof may be utilized during the subassembly manufacturing 1608 andsystem integration 1610, for example, by substantially expeditingassembly of or reducing the cost of an aircraft 1602. Similarly, one ormore of apparatus embodiments, method embodiments, or a combinationthereof may be utilized while the aircraft 1602 is in service, forexample and without limitation during the maintenance and service 1616.Thus, the invention may be used in any stages discussed herein, or anycombination thereof, such as specification and design 1604, materialprocurement 1606, component and subassembly manufacturing 1608, systemintegration 1610, certification and delivery 1612, service 1614,maintenance and service 1616) and/or any suitable component of aircraft1602 (e.g., airframe 1618, systems 1620, interior 1622, propulsionsystem 1624, electrical system 1626, hydraulic system 1628, and/orenvironmental 1630.

In one embodiment, a part comprises a portion of airframe 1618, and ismanufactured during component and subassembly manufacturing 1608. Thepart may then be assembled into an aircraft in system integration 1610,and then be utilized in service 1614 until wear renders the partunusable. Then, in maintenance and service 1616, the part may bediscarded and replaced with a newly manufactured part. Inventivecomponents and methods may be utilized throughout component andsubassembly manufacturing 1608 in order to manufacture new parts.

Any of the various control elements (e.g., electrical or electroniccomponents) shown in the figures or described herein may be implementedas hardware, a processor implementing software, a processor implementingfirmware, or some combination of these. For example, an element may beimplemented as dedicated hardware. Dedicated hardware elements may bereferred to as “processors”, “controllers”, or some similar terminology.When provided by a processor, the functions may be provided by a singlededicated processor, by a single shared processor, or by a plurality ofindividual processors, some of which may be shared. Moreover, explicituse of the term “processor” or “controller” should not be construed torefer exclusively to hardware capable of executing software, and mayimplicitly include, without limitation, digital signal processor (DSP)hardware, a network processor, application specific integrated circuit(ASIC) or other circuitry, field programmable gate array (FPGA), readonly memory (ROM) for storing software, random access memory (RAM),non-volatile storage, logic, or some other physical hardware componentor module.

Also, a control element may be implemented as instructions executable bya processor or a computer to perform the functions of the element. Someexamples of instructions are software, program code, and firmware. Theinstructions are operational when executed by the processor to directthe processor to perform the functions of the element. The instructionsmay be stored on storage devices that are readable by the processor.Some examples of the storage devices are digital or solid-statememories, magnetic storage media such as a magnetic disks and magnetictapes, hard drives, or optically readable digital data storage media.

Although specific embodiments are described herein, the scope of thedisclosure is not limited to those specific embodiments. The scope ofthe disclosure is defined by the following claims and any equivalentsthereof.

1. A method for assembling a wing, the method comprising: coupling arobot arm to a bracket that is attached to a rib held against a wingpanel; and operating the robot arm to install one or more shims betweenthe rib and the wing panel while the robot arm is coupled to thebracket.
 2. The method of claim 1, further comprising mounting thebracket to the rib.
 3. The method of claim 2, further comprising holdingthe rib against the wing panel. 4-5. (canceled)
 6. The method of claim2, wherein mounting the bracket to the rib comprises aligning thebracket with indexing features at the rib.
 7. The method of claim 2,wherein the bracket is detachably mounted to the rib.
 8. The method ofclaim 1, wherein the bracket enforces a desired contour onto the rib. 9.The method of claim 1, further comprising indexing a position of therobot arm relative to the bracket.
 10. The method of claim 1, whereinthe robot arm is detachably coupled to the bracket.
 11. The method ofclaim 10, further comprising decoupling the robot arm from the bracketsubsequent to operating the robot arm to install one or more shims. 12.The method of claim 11, further comprising iteratively coupling a robotarm, and operating the robot arm to install one or more shims, for eachof a plurality of ribs held against the wing panel.
 13. The method ofclaim 1, further comprising driving the robot arm along the bracket toalign the robot arm with shim locations along the rib to wing panelinterface.
 14. The method of claim 1, further comprising inspecting therib to wing panel interface.
 15. The method of claim 14, whereininspecting the rib to wing panel interface is performed by operating therobot arm.
 16. The method of claim 14, wherein inspecting the rib towing panel interface is performed via an end effector of the robot armto identify locations for shims.
 17. The method of claim 14, furthercomprising determining whether a gap at the rib to wing panel interfaceis greater than a shimming tolerance threshold.
 18. The method of claim17, further comprising selecting a shim based on a size of a gap that isgreater than the shimming tolerance threshold.
 19. The method of claim17, further comprising fabricating a shim based on a size of a gap thatis greater than the shimming tolerance threshold.
 20. The method ofclaim 1, further comprising delivering the shim via a feeder line to therobot arm.
 21. The method of claim 1, further comprising fastening therib to the wing panel.
 22. The method of claim 21, wherein fastening therib to the wing panel is performed subsequent to operating the robot armto install one or more shims.
 23. The method of claim 22, whereinfastening the rib to the wing panel is performed subsequent to operatingthe robot arm to install all of the one or more shims.
 24. The method ofclaim 1, wherein the wing panel is an upper wing panel held against anupper edge of the rib, and wherein the method further comprises,subsequent to operating the robot arm to install one or more shimsbetween the rib and the upper wing panel, holding a lower wing panelagainst a lower edge of the rib.
 25. The method of claim 24, furthercomprising operating the robot arm to install one or more shims betweenthe rib and the lower wing panel while the robot arm is coupled to thebracket.
 26. A method of shimming a rib of an aircraft, the methodcomprising: coupling a robot arm to a bracket that is attached to a ribheld against a wing panel; and operating the robot arm to install one ormore shims between the rib and the wing panel while the robot arm iscoupled to the bracket.
 27. A non-transitory computer readable mediumthat comprises programmed instructions configured to control an assemblysystem for a wing, such that the assembly system comprises: a robot armcoupled to a bracket that is attached to a rib held against a wingpanel; and the robot arm configured to install one or more shims betweenthe rib and the wing panel while the robot arm is coupled to thebracket. 28-51. (canceled)
 52. A method of assembling a portion of anaircraft, the method comprising a processor executing programmedinstructions stored on a computer readable medium and controlling:coupling a robot arm to a bracket that is attached to a rib held againsta wing panel; and operating the robot arm to install one or more shimsbetween the rib and the wing panel while the robot arm is coupled to thebracket.
 53. A system configured to assemble a wing, such that thesystem comprises: a carriage coupled to a bracket attached to a rib; anda robot arm that extends from the carriage and that is operable operform work upon an interface between the rib and a wing panel. 54-65.(canceled)
 66. A method of fabricating a portion of an aircraft, themethod comprising: coupling a carriage to a rib; extending a robot armcomprising an end effector from the carriage; and the end effectorperforming work upon an interface between the rib and a wing panel. 67.An apparatus configured to assemble wing, such that the apparatuscomprises: a robot arm dimensioned for placement at an interface betweena rib and a wing panel, such that the robot arm comprises an endeffector configured to perform work upon the interface, the work beingselected from a group that consists of: an inspection of the interface,an installation of a shim at the interface, and an installation offasteners at the interface. 68-69. (canceled)
 70. A method offabricating a portion of an aircraft, the method comprising: placing arobot arm comprising an end effector at an interface between a rib and awing panel; and performing work upon the interface, the work beingselected from a group consisting of: inspecting the interface,installing a shim at the interface, and installing fasteners at theinterface.